Python/FastAPI Developer — Voice Bot Telephony & Speech Integration (Fintech)

@vishal1145

Your call-state machine will fail the moment a customer's phone is switched off or they hang up mid-authentication. Right now you're handling happy-path flows, but production telephony requires retry logic, dead-letter queues for failed callbacks, and idempotent transaction logging - otherwise your audit trail breaks and the bank's compliance team will reject the pilot before it even starts. Quick question - what's your strategy for handling Exotel webhook retries when your server is temporarily down, and are you planning to store call recordings separately from transcripts to meet RBI's data retention mandates? Here's the architectural approach: - TELEPHONY INTEGRATION: Build async webhook handlers for Exotel's call-status events (answered/busy/failed) with exponential backoff retry logic and DLQ for poison messages - SPEECH PIPELINE: Integrate Sarvam AI's streaming STT/TTS with fallback to DTMF when speech confidence drops below 0.7, critical for noisy mobile networks in tier-2 cities - POSTGRESQL SCHEMA: Design partitioned tables for call_records (by month) and immutable audit_log with WORM constraints, indexed on customer_phone + timestamp for sub-50ms regulatory queries - SECURITY HARDENING: Implement rate-limiting per phone number, rotate HMAC secrets via environment config, add request signing validation for all Exotel callbacks, and structured logging for SOC audit trails - NOTIFICATION ORCHESTRATION: Wire Exotel SMS + SMTP into a unified event bus so every state transition triggers exactly-once delivery with idempotency keys I've integrated Twilio and Plivo for 2 fintech products that processed 40K+ calls/month under RBI oversight. Let's schedule a 20-minute technical call to walk through your existing state machine and map the failure scenarios before the bank's security review.

@sajjadtaghvaeifr

Hello, I trust you're doing well. I am well experienced in machine learning algorithms, with nearly a decade of hands-on practice. My expertise lies in developing various artificial intelligence algorithms, including the one you require, using Matlab, Python, and similar tools. I hold a doctorate from Tohoku University and have a number of publications in the same subject. My portfolio, which showcases my past work, is available for your review. Your project piqued my interest, and I would be delighted to be part of it. Let's connect to discuss in detail. Warm regards. please check my portfolio link: https://www.freelancer.com/u/sajjadtaghvaeifr

@KarthikTechCon

Hi, I'm Karthik with 15+ years of experience in Python, FastAPI, AI voice solutions, and enterprise backend development. I can help take AffirmoBot from a working prototype to a production-ready banking solution. My expertise includes FastAPI, PostgreSQL, secure REST APIs, telephony integrations (Exotel/Twilio/Plivo), speech AI integration, and scalable backend architecture. I'll implement real outbound calling, integrate Hindi/Hinglish STT/TTS (Sarvam AI or equivalent), migrate sessions and audit logs to PostgreSQL, strengthen security with HMAC validation and API hardening, and integrate SMS/Email notifications into the live workflow. I follow clean coding practices, comprehensive testing, GitHub PR workflows, and detailed documentation to ensure the solution passes bank security reviews. I'm comfortable working independently, providing regular updates, and delivering milestone-based progress within your 4–6 week timeline. I'd be happy to discuss the architecture and implementation plan. Best Regards, Karthik

@TechizeBuilder

Hi! I read "Python/FastAPI Developer — Voice Bot Telephony & Speech Integration (Fintech)" carefully and I'm confident we can deliver. We bring extensive hands-on experience delivering enterprise-grade solutions across many industries—ERP, CRM, HRMS, LMS, web and mobile apps, e-commerce, healthcare, travel, real estate and logistics—with strong skills in Java, Python, Mobile App Development, Android, PostgreSQL, API Development. Whatever your domain, we build secure, reliable software that's on time and within budget. Let's connect to discuss your goals, timeline and budget. Thanks!

@abhishek060

Hi, I can help take your existing FastAPI proof of concept to a production-ready solution. I have experience with Python, FastAPI, PostgreSQL, API integrations, and building secure backend systems. I can integrate real outbound calling with Exotel/Smartflo, implement speech-to-text and text-to-speech, migrate the application to PostgreSQL, strengthen the existing security, and connect SMS and email notifications into the live workflow while maintaining clean, well-documented code. I have one quick question: Have you already finalized Exotel/Smartflo and Sarvam AI for the production deployment, or are you still open to recommendations? I've reviewed your requirements and would be happy to discuss the project in more detail. Once we connect, I can share my approach, timeline, and cost estimate. Looking forward to hearing from you

@iimtpradeepdash

Telephony integration always trips up at provider edge-cases: live call initiation, hangups, unreachable numbers. I’ve integrated Exotel and Plivo APIs (outbound/IVR, India DLT-compliant) for a fintech support platform last year, so I know the traps: retries, webhooks, status reconciliation. What I’d do: refactor call logic to use Exotel or Tata, handle all call-status events, then wire up Sarvam AI for Hindi/Hinglish speech (I’ve used Google STT and AWS Transcribe for Indian languages; Sarvam’s similar—happy to swap to your pick). PostgreSQL schema with audit logging for 5+ years is straightforward; I can design for audit trail + GDPR. Security review: I run code through OWASP, tighten the callback signing, and document every endpoint. Are there any integration blockers from Exotel or Smartflo yet, like call queue limits or DLT paperwork pending? Can start once code access is set. Pradeep

@UzeeTech

Building AffirmoBot to help Indian banks with their telephony transactions is no ordinary task, but luckily for you, I am no ordinary Python developer. With 7+ years of experience in developing and deploying complex backend systems, including the use of FastAPI which your product currently utilizes, I have the unique blend of skills you need for this project. My proficiency extends beyond voice automation infrastructure. Having worked extensively with PostgreSQL, I understand the importance of database Schema design for long-term storage needs- an indispensable feature given your regulatory requirement to retain data for 5+ years. I also possess a deep knowledge in DTMF/keyword matching and extensive experience in integrating Sarvam AI or equivalent services for Hindi/Hinglish speech recognition making me a perfect fit for this project as well. Moreover, as someone who has an eye for security implementation and measures, I can promise that your project will be put through thorough examinations before reaching production readiness. Once deployed, my obsession with clean code and meticulous documentation will enable your team to navigate confidently through changes in the codebase in the future. This opportunity is truly exciting because not only does it require all my valued experiences but can also be leveraged to build upon a bot that will revolutionize automated phone call verification in Indian banking sector making it more secure than ever before!

@letscms

Hi, I have 12+ years of backend development experience with Python, FastAPI, PostgreSQL, Docker, and secure API development. Your existing architecture provides a solid foundation, and I can help transition it from a working prototype to a production-ready platform for your banking pilot. I can integrate Exotel or Tata Tele Smartflo for outbound calling, implement Sarvam AI (or an equivalent STT/TTS provider), migrate session and audit data to PostgreSQL with a scalable schema, and strengthen security for bank compliance by reviewing API authentication, HMAC callbacks, validation, and logging. I'll also integrate your existing SMS and email notification modules into the live workflow, extend the current automated test suite, and ensure the solution remains clean, well-documented, and production-ready. I'm comfortable working independently through GitHub PRs with regular progress updates and can start immediately. Best Regards Jitendra Sharma

@nitinjohnson316

Hi, I am a Full Stack Developer with 14+ years of experience building CRM systems, ERP integrations, SaaS platforms, and business applications. I can help with: • Custom CRM development • Lead and sales pipeline management • Quote and approval workflow • ERP integration using REST or SOAP APIs • Customer, product, and order management • Secure and scalable application development • Testing, deployment, and ongoing support I have experience with Laravel, PHP, React, Node.js, MySQL, API integrations, and custom business software. I can complete the work quickly with good quality and provide regular project updates.

@FreeLancers360

Hi there, The moment I read "Python/FastAPI Developer — Voice Bot Telephony & Speech Integration (Fintech)", I knew it was a strong match for exactly what we do best. I love turning a solid brief like yours into a polished result you’ll be proud to put your name on. From your brief I can see this involves android, mobile app — all areas we handle in-house. We specialise in Java, Python, Mobile App Development, Android, which lines up directly with what you need. How we'd approach it: - Finalise the screens, user flows and feature list with you - Build smooth, native-feeling UI with clean, maintainable code - QA on real devices, then prepare and ship to the store(s) - Post-launch support and iteration once you’re live Delivering at the scale of 21 checks is no problem for us — we're set up for volume without dropping quality. Happy to work hourly with transparent time tracking and regular check-ins. I’ll fold in your feedback fast and keep refining until the result feels exactly right to you. Happy to jump on a quick chat to walk through scope and timelines whenever suits you. Best regards, FreeLancers360 Let’s connect in chat and get started — message me anytime and I’ll reply right away!

@jagratip3

I can take AffirmoBot from prototype to production-ready and help you make it bank-pilot compliant. I’ve worked on similar FastAPI systems with real-time state machines, external API orchestration, and production-grade reliability requirements. My focus would be safely replacing your mock layer with Exotel/Tata Smartflo for outbound calling, integrating Sarvam AI (or equivalent) for Hindi/Hinglish STT/TTS, and ensuring full call-state tracking with retries and failure handling. I’d redesign your in-memory session layer into a proper PostgreSQL schema (calls, transcripts, audit logs with retention support), while keeping your existing state machine and API structure intact. I’d also harden auth, HMAC callbacks, and validation for banking security review standards. Deliverables would include production deployment readiness, extended test coverage, and clean documentation for audit/compliance.

@gsantharam7088

Hello, Your project is well-structured, and I'd be excited to help take AffirmoBot from a working prototype to a production-ready platform. I have experience developing scalable backend applications with Python, FastAPI, PostgreSQL, REST APIs, third-party integrations, and secure cloud deployments. I can integrate Exotel or Tata Tele Smartflo for outbound calling, implement Sarvam AI for Hindi/Hinglish speech recognition, migrate your in-memory sessions to a well-designed PostgreSQL schema with long-term audit storage, and strengthen the application for security reviews through improved authentication, callback validation, and API hardening. I can also integrate SMS and email notifications into the live call workflow while extending your existing automated test suite. I follow clean coding practices, GitHub-based workflows, and provide regular progress updates throughout development. I'm comfortable working independently, collaborating asynchronously, and delivering milestone-based releases with complete documentation. I am available to start immediately and would be happy to discuss the architecture, timeline, and production rollout strategy. Best Regards, Santharam G

@azwa04

I’ll take your existing FastAPI proof-of-concept and make it production-ready by integrating Exotel/Tata Smartflo, Sarvam AI speech services, and PostgreSQL with a scalable architecture. I'll strengthen security by reviewing API authentication, HMAC callbacks, input validation, and audit logging to meet banking standards. The existing test suite will be extended while integrating notifications and handling complete call lifecycle scenarios. My focus will be on clean, well-documented, production-quality code that is ready for a successful bank pilot.

@TechWagger2026

With over 14 years of experience in web and mobile app development, I've become adept at finding elegant solutions for complex problems. My skills are particularly aligned with your project's requirements: robust backend development with Python (including good knowledge of FastAPI), extensive experience with API integrations (including telephony/VoIP APIs like Exotel and Twilio), and the ability to design scalable databases like PostgreSQL - exactly what you need for AffirmoBot. The effort you've put into providing me with a strong foundation helps us hit the ground running. Once we begin, I'll bring my eye-for-detail to improve your existing APIs, validate inputs meticulously and harden security measures in preparation for a bank security review. I'll seamlessly integrate Sarvam AI for Hindi/Hinglish speech recognition, facilitate outbound calling via Tata Tele Smartflo/Exotel, move your session & audit-logs storage smoothly to PostgreSQL and ensure real-time notifications via SMS & email. Whether it’s extending an already working automated test suite or setting new milestones - you have a dependable partner in me! Let's turn AffirmoBot into a fully viable product together!

@rishi9343

Hi, I've gone through your project details and I'm interested in helping you with AffirmoBot. I can assist with integrating Exotel for outbound telephony, setting up PostgreSQL for production database, and improving API security for the bank review. I'll work on replacing the simulated call flow, integrating Sarvam AI for speech recognition, and.

@KrisuTechkul

Hi, I’m Krishna from Delhi. Thank you for the opportunity to submit our proposal for your project. We have carefully reviewed the project details, and based on our experience, my team and I are confident in our ability to deliver a successful solution. We are a team of 20+ AI engineers and have successfully completed 300+ projects across various domains. I would appreciate the opportunity to schedule a brief discussion to better understand your requirements and expectations. This would also allow us to share our approach and demonstrate how our expertise can add value to your project. Additionally, we have recently worked on similar projects and would be happy to share relevant insights and learnings that may be beneficial for your initiative. Looking forward to connecting with you. Thanks & Regards, Krishna Kant KrisuTechkul

@ziedb4

Hi, AffirmoBot is exactly the kind of project I enjoy — taking a working FastAPI prototype to production-grade with real telephony, proper persistence, and bank-level security hardening. Here's how I'd approach each module: 1. Outbound Telephony (Exotel or Tata Tele Smartflo) - Replace simulated flow with real outbound call trigger via Exotel API - Handle all call-status callbacks: answered, busy, switched off, unreachable - Integrate cleanly into your existing state machine (auth → capture → confirm/deny → done) 2. Speech Recognition (Sarvam AI or equivalent) - Wire STT into the DTMF/keyword matching layer as primary input - Fallback to DTMF on recognition failure 3. PostgreSQL Migration - Schema design for call records, transcripts, and audit trails with 5+ year retention - Replace in-memory session storage with proper async DB layer (SQLAlchemy + asyncpg) 4. Security Hardening - Review API-key auth, HMAC-signed callbacks, and input validation - Prepare clean documentation for bank security review 5. Notifications - Wire Exotel SMS and SMTP email into call outcome events I work independently, communicate clearly, and am comfortable with async updates and PR-based reviews on GitHub.

@tamannarajput18

Having navigated the complexities of building production-ready, secure and scalable applications as a Full Stack Developer over the years specializing in MEAN and MERN stack development, I am well-positioned to take your voice-automation product affirmoBot to the next level. Moreover, my prior experience in harnessing AI solutions for workflow automation also aligns with your need for speech recognition integration that involves real-time Hindi/Hinglish speech-to-text and text-to-speech conversion capabilities using Sarvam AI or equivalent systems. Lastly, my ability to work diligently, communicate effectively and independently make me an ideal fit for your project. You can expect daily updates, weekly calls via Slack/WhatsApp; all code reviewed through GitHub- making it an interactive and transparent collaboration.

@sgwtechnology

Hi, Your project aligns well with my backend expertise. I have strong experience with Python, FastAPI, PostgreSQL, API security, and third-party integrations, including telephony, webhooks, and asynchronous workflows. I can replace the simulated call flow with Exotel/Smartflo, integrate Sarvam AI for Hindi/Hinglish STT/TTS, migrate sessions and audit logs to PostgreSQL, strengthen security for bank compliance, and integrate SMS/email notifications. I write clean, production-ready code, follow GitHub PR workflows, and provide regular progress updates. I'm available to start immediately and deliver a stable, scalable solution for your bank pilot.