Software Architect / System Architect

@Prutheus

Reviewing a closed-loop financial platform that already has a team and a running system is a specific kind of job: the useful output is not a beautiful target architecture, it is a prioritised list of what will actually hurt you and in what order. Where I would look first, because this is where closed-loop systems fail: - Ledger integrity. Balances must be derivable from an immutable transaction log rather than stored and mutated. If a balance is a column that gets updated, you will eventually have money that does not reconcile and no way to find out why. - Idempotency and concurrency on deposits, withdrawals and trades. Double-submitted requests and racing transactions are not edge cases at volume. - Consistency boundaries — which operations must be atomic, and where eventual consistency is acceptable. Getting this wrong is the most expensive mistake to fix later. - Access control and audit: who can move money, what is recorded, and whether the record can be altered. - Reconciliation as a designed capability rather than a manual spreadsheet. Deliverable: written architecture documentation with the current-state gaps, the target flows, and clear guidance your developers can implement against — plus the risk ranking so you can sequence it. Background: production platforms with database-enforced access control, PostgreSQL data modelling as my core work, and eighteen services running in production for one client. Question: what is the current stack, and is there a specific incident or concern that prompted this review? Martin

@Muhammadzeesha59

Hello Sir/MAM I am a Skilled Full Stack Developer. Having rich experience in Java , C++ , C , C# , Python , Eclipse , Sql , Mysql , .Net ,Oracle , Object Oriented Programming , Data Structure , Algorithms, Linux , Windows , Cloud , Azure , Ubuntu , OpenAI , Desktop Applications. Web Development I have a perfect grip on “Artificial Intelligence” “Automation” , and work in “Machine Learning” Deep Learning “Computer Vision ” Object Detection”. My track record as demonstrated in my 100% job completion and 5-star review rating showcases My ability to deliver exceptional results on time and with utmost quality I believe that my skill set makes me the ideal candidate for this project Please come on chat we will discuss more about this I will be waiting for your reply . Thanks and Best Regards

@ozbas

As an experienced Full-Stack software engineer with more than a decade's worth of experience, I have had the unique opportunity to work on diverse projects across different industries. What sets me apart is my ability to understand and adapt to the specific needs of each project. I've successfully designed and implemented complex systems involving user accounts, transactions, payments, and detailed administration interfaces - all key components of your financial platform. Having skillfully used backend technologies such as PHP (Laravel & CodeIgniter), Node.js/Express.js, Java and ASP.NET in multiple payment gateway integrations like PayPal, Braintree, and Stripe as well as integrating blockchain technologies for digital assets management, I believe that my expertise is directly aligned with your project requirements. Furthermore, I am not just focused on piecemeal solution delivery, instead, I prioritize strong overall system architecture for seamless integration and end-to-end performance. Your closed-loop financial platform is in great hands with me. I am confident in my capability to review your existing setup, identify areas that need improvement or re-designs and provide comprehensive technical guidance. My aim is to ensure your development team has a robust architecture documentation that serves as a useful roadmap for future iterations. Working with you will be a brilliant journey where we shape the fintech industry together!

@modesorehari6

Hello! I have experience designing and reviewing complex financial and transaction-based systems, including backend architecture, data modeling, APIs, database design, and scalable enterprise platforms. I can help with FinTech architecture, system flows, UML diagrams, and technical documentation. I will review your current system, identify architecture gaps, improve scalability and security, define clear workflows for accounts, balances, transactions, payments, wallets, and administration, and provide guidance your development team can follow. Q1: What technologies and architecture are currently used in the existing platform? Q2: Do you already have documentation or diagrams of the current system? Timeline: 2 weeks I am available to start immediately and have free time now. I respect your existing team's approach and suggestions, and I am interested in building a long-term working relationship by providing reliable architecture support. Thanks

@mayankinnovative

Hello I reviewed your Software Architect and System Architect project and it stood out because good architecture needs to balance scalability security performance maintainability and real business requirements from the beginning Problem Software systems can become expensive to evolve when architecture decisions are made without considering service boundaries data flows scalability security integrations and long term maintenance Solution I can analyze your existing or planned system requirements and design a robust architecture covering application layers APIs databases authentication integrations cloud infrastructure and deployment I can define service boundaries data models communication patterns and scalability strategies while documenting the architecture clearly for the development team I can also review existing code and identify architectural bottlenecks or technical debt Result You will receive a practical scalable and maintainable system architecture with clear technical decisions documentation and an implementation path that reduces future development and infrastructure risks A few questions Is this architecture for a new product or an existing system What is the expected user and transaction scale Which technologies and cloud services are currently being considered Do you need architecture documentation diagrams and technical specifications I can start immediately and provide regular progress updates throughout the project Thanks

@tyronet2

Architecture review and design for a closed-loop financial platform — accounts, balances, transactions, deposits/withdrawals, trading, payments, wallet, admin. Reviewing what your team already built, identifying gaps, and delivering clear docs your devs can execute against, not throwing away work that's already shipped. My review approach: start with the transaction model, because that's where financial systems break. Double-entry ledger or single-entry with audit log? Idempotency keys on every write path? How are concurrent balance updates handled — pessimistic lock, optimistic concurrency, or event-sourced with projections? Reconciliation strategy between internal ledger and external payment/trading systems? Then flow through deposits/withdrawals (webhook idempotency, retry semantics, settlement lag handling), trading engine (order matching, position accounting, fee application ordering), and wallet (custody model, key management if digital assets are involved, cold/hot separation).

@PINESCRIPTERR

Hi, The central challenge in a closed-loop financial platform is maintaining one authoritative, auditable financial truth across balances, trades, payments, deposits, withdrawals, wallets, and administrative actions, especially when requests retry or external services fail midway. I’d begin with an architecture and threat-model review of the existing system: service boundaries, database schema, balance calculations, transaction states, authentication, RBAC, integrations, deployment, and operational controls. I’d trace critical flows end-to-end and test for double spending, duplicate webhooks, race conditions, partial settlement, rounding errors, privilege escalation, and reconciliation gaps. The target design should use an immutable double-entry ledger, idempotency keys, atomic postings, explicit state machines, currency-safe decimal handling, maker-checker controls for sensitive admin actions, and complete audit trails. Trading balances should distinguish available, reserved, pending, and settled funds. External payment events would pass through durable queues with retries, dead-letter handling, and daily reconciliation rather than directly mutating balances. Deliverables would include system and data-flow diagrams, trust boundaries, ledger model, API/event contracts, sequence diagrams, risk register, prioritized remediation roadmap, and implementation guidance for the development team. Regards, Houssame

@CauaAlves

Closed-loop financial platforms usually leak consistency at the ledger boundary, where balances get updated outside the transaction flow and reconciliation breaks weeks later. I'd review your current setup for exactly that class of gap, map the account/balance/transaction/wallet flows end-to-end, and deliver architecture documentation your dev team can implement against directly, not just diagrams. What's the current stack (languages, database), and is double-entry accounting already part of the ledger design or is that one of the gaps to address?

@ankits0192

Hi, You need a thorough review of your financial platform’s architecture, gap analysis, and detailed design documentation. I see you require: 1) assessment of current system components, 2) identification of security and scalability gaps, 3) redesign of data flows for accounts, balances, and transactions, 4) UML diagrams and technical specs for developers, and 5) guidance aligned with FinTech best practices. I will audit the existing codebase, map current UML, run a gap analysis, then produce a revised architecture using UML and data‑model diagrams, plus a step‑by‑step implementation guide. I previously delivered a real‑estate marketing site with complex property listings and full documentation, demonstrating my capability to craft clear, scalable architectures. I provide an upfront estimate, send regular progress updates, test the design against edge cases, and hand over complete docs. What core tech stack does the current platform use? Are there compliance standards (e.g., ISO 20022) to follow? Looking forward to your reply.

@thiagofoz87

Your platform already covers several high-risk financial domains — balances, transactions, wallets, payments, trading flows, and administration — so the most important part is ensuring consistency, traceability, scalability, and operational safety across all services. I can help by reviewing the current architecture, identifying bottlenecks and structural risks, and producing a clear target architecture with practical guidance for your existing development team. My approach would include: - Analysis of transaction flows, balance consistency, and failure recovery strategies - Review of service boundaries, event-driven communication, and data ownership - Evaluation of scalability, concurrency handling, and auditability - Architecture recommendations for wallets, deposits/withdrawals, trading operations, and admin workflows - Infrastructure and deployment review for reliability and observability - Documentation of system flows, integrations, and technical decisions for implementation alignment My background is heavily focused on high-availability backend systems using Kotlin/Java, Spring Boot, AWS, distributed services, messaging systems, and financial-grade architectures handling critical transactional workloads. For this engagement, I would structure the delivery into architecture assessment, technical recommendations, and implementation-oriented documentation so your team can execute with minimal ambiguity.

@mrabdulbaki

Hello, Your project strongly matches my experience in designing transaction-heavy business and financial systems. I have hands-on experience architecting ERP and financial platforms involving accounting ledgers, balances, payments, transaction posting, approvals, user roles, audit trails, APIs, reporting, and complex operational workflows. For your existing platform, I can first review the current architecture, database, APIs, transaction logic, and security model. I’ll then identify gaps and provide a clear architecture covering wallets, balances, deposits/withdrawals, trading, payments, reconciliation, administration, and failure handling. A key focus will be transaction integrity: preventing duplicate transactions, incorrect balances, race conditions, partial processing, and ensuring every financial movement is traceable and auditable. I can provide clear architecture diagrams, transaction flows, technical documentation, and practical guidance your existing developers can directly implement. I’m ready to review the current system and start immediately. Best regards, Ayssar

@roell3

Hello The hardest part is usually aligning data quality, evaluation, and production monitoring with real-world latency and compliance constraints. Integration with existing systems and clear ground truth often drive most of the early risk. What does the current stack look like for ingestion and deployment? Are there SLAs or compliance boundaries I should plan around? Is the work batch-only or does it require real-time inference? Looking forward to learning more about the architecture.

@toqeer74

Hi there, I understand you're looking for an experienced Software Architect to design and review the architecture of your closed-loop financial platform. With my background in architecting financial applications, I can evaluate your current setup, identify any gaps, and design a complete architecture that covers all functionalities, including user accounts, transactions, and payments. I've worked on a similar platform where I provided architectural oversight and documentation, ensuring clarity for developers. My experience in FinTech and transaction-heavy systems positions me well to deliver what you need in just 7 days. Could you share more about the specific technologies your current system uses?

@josephexpert

As a seasoned Software Architect with hands-on experience in FinTech and transaction-heavy financial systems, I am confident that I can breathe new life into your closed-loop financial platform. I am well-versed in designing and reviewing software architectures, identifying gaps, and providing clear technical guidance ─ precisely what you need for your project. In fact, reviewing your existing setup to understand possible improvements is a task I find particularly engaging. My expertise spans across different programming languages including C++, C#, Python; and platforms such as Node.js and Laravel which will be valuable in enhancing the functionality of your payment, trading, and wallet features. Additionally, my knowledge in eCommerce and payment gateway integration will prove beneficial when ensuring the user accounts, balances, transactions reflect accurately. Furthermore, my proficiency in software engineering and Docker equips me with the ability to troubleshoot and debug complex systems like yours. You can trust me to provide an efficient architectural design not only by leveraging my extensive skills but also by drawing from my risk management background to anticipate potential issues in your platform. Besides designing a robust architecture for your platform, I possess great documentation skills which will provide useful guidance for your development team.

@predragr3

✅✅✅ Hi, there ✅✅✅ I am thrilled to submit my proposal for the role of Software/System Architect for your closed-loop financial platform. With over 8 years of experience in designing and reviewing system architectures for various FinTech and transaction-heavy financial systems, I am confident in my ability to deliver exceptional results for your project. Having worked on similar systems in the past, I understand the critical importance of user accounts, transactions, trading functionalities, and security measures within a financial platform. My expertise in developing architecture documentation and providing clear technical guidance will ensure seamless integration with your existing system. My approach involves conducting a thorough review of your current setup, identifying any gaps or inefficiencies, and designing a robust architecture that optimizes performance and security. I will collaborate closely with your development team to ensure a smooth implementation process and provide ongoing support as needed. Feel free to reach out with any questions or to discuss further details. ✌️ Predrag ✌️

@thaakierj

Hi there, we have recently completed a similar project and would love to share some references. Your closed-loop financial platform sounds right up our alley and we would love to exceed your expectations. Understanding the need for a reliable architecture that encompasses user accounts, transactions, and payments, we can provide a polished design that identifies gaps and enhances functionality. Our extensive experience in FinTech and transaction-heavy systems ensures we deliver a seamless and integrated solution. While we might be new to Freelancer, we have over 5 years of experience off-site and I truly appreciate you taking your time to review our proposal and I would love to discuss this project more. Kind regards, Thaakier

@Firasatw

As a highly skilled Senior Full-Stack Architect, my 11 years of experience align perfectly with the demands of your project. My track record in designing high-performance web applications and digital platforms is testimony to my ability to devise system architectures that prioritize speed, security, and scalability—all of which are critical in the financial domain. Grokking the ins and outs of transaction-heavy systems and FinTech solutions has lent me unique insights into database management, which I deftly handle by combining SQL and MongoDB for optimal results. By designing "data-focused" architectures, I ensure your platform will remain responsive even amidst heavy load. But my value extends beyond technical proficiencies. I take pride in being a bridge between engineering and business—understanding the operational aspects of your system as well as its technical intricacies. This perspective enables me to create architectures that don't just meet functional requirements but ones that also anticipate future needs. Another feather in my cap is my knack for leading cross-functional teams. Please take a moment to explore my portfolio: https://www.freelancer.com/u/Firasatw If my style and expertise align with your vision, I’d love to discuss how I can bring your project to life. Let’s connect budget and deadline can be finalized during our chat. Best regards, Firasat W

@affanq3

Hello, Primary risk is inconsistent money movement semantics across modules causing balance drift between user accounts, wallets, trading engine and payments. I would focus first on end-to-end transaction atomicity, idempotency tokens, deterministic reconciliation jobs, and a single source of truth for ledger events so that deposits/withdrawals, trading, payments and internal transfers never diverge. I have delivered architecture reviews and designs for multiple transaction-heavy systems: a custodial wallet and settlement service for digital assets, a trading gateway integrated with exchange matching engines, and a bank-grade ledger used for internal clearing and reconciliation. In those engagements I reviewed existing codebases, identified gaps in event sourcing, designed a canonical ledger model, and produced clear architecture docs and sequence diagrams for developers to implement. Those projects required strict audit trails, retry-safe flows, and clear admin controls for dispute handling. I will start by running a targeted architecture review: gather existing sequence diagrams, database schemas, messaging flows and authentication/authorization rules, then produce a short gap analysis and a proposed canonical ledger model. The first deliverable will be a concise architecture diagram plus a prioritized list of fixes with estimated effort. - Do you have an existing canonical ledger or is balance state distributed across modules? - Can you share a recent incident or reconciliation failure to guide the initial gap analysis? Best regards, Affan Qureshi

@warrick1718

This project immediately caught my attention because it is exactly the type of work I do best. Your need for a Software Architect to design and review a closed-loop financial platform resonates with my expertise in creating clean, professional, user-friendly systems. I understand the importance of seamless integration and automated processes in financial applications. While I am new to freelancer, I have tons of experience and have done other projects off site, including architecture for payment systems and trading platforms. My portfolio includes successful designs that focused on security, scalability, and user experience. If this sounds like what you're looking for I'd love to hear more about your project. Regards, Warrick Van Eeden