Backend Developer — User Verification System (KYC Logic)

Budget: 27000 UAH Deadline: 1 day

✋ Hello! We are the IT company dZENcode.

We are implementing a scalable KYC system with a REST API, secure storage of personal data, decision-making logic (approve/decline/review), action logging, and the ability to integrate with third-party verification providers, based on the team's experience, best practices, and our own developments.

Are you planning to use third-party KYC services for document verification, or should the system be completely autonomous?
What level of compliance is required — for example, GDPR, data storage, audit?

You can find detailed information about our services and rates on our website: Freelancehunt
Take a look – we will discuss the details of the work further, write when you are ready.

The final cost is determined only after clarifying the scope and requirements.

___________________
Sincerely,
Manager of dZENcode

Our strengths:
💎 10+ years providing IT services: Outsourcing, Outstaffing
🔥 90+ in-house specialists
🚀 Projects "from scratch" and for support
⚙️ SLA and post-production support
✅ Contract with the company, guaranteed results!
🔥 250+ public reviews since 2015. Expand

Budget: 27000 UAH Deadline: 30 days

Hello. I have extensive experience with Django/FastAPI. I am ready to collaborate. Please contact me.

Budget: 27000 UAH Deadline: 14 days

Good day. I specialize in CRM, dashboards, databases, and web services for processing, accounting, and analytics. Convenient and modern design. Development is fully turnkey.

Integration with artificial intelligence and other automations can be implemented. CRM is my main focus, so I can offer many interesting options.

Feel free to reach out.

Budget: 27000 UAH Deadline: 7 days

Hello, I worked on a user verification system for a fintech startup that processes KYC documents, which handled over 10,000 requests per day with 95% accuracy in automatic recognition ✅

Which specific verification providers are you considering for integration, or are you planning to create a completely in-house solution for document verification?

I suggest we get in touch; I will provide you with free technical consultation and we can create a development plan + I will tell you about my team!

Budget: 27000 UAH Deadline: 1 day

I will do everything with great pleasure! It will be done quickly and efficiently, I am ready to start working right now!

Budget: 27000 UAH Deadline: 14 days

Hello, Evgeny.

I read the technical specifications — the task is clearly outlined: KYC-flow from scratch on FastAPI + PostgreSQL, decision engine (approve / reject / re-request), REST API for external integrations, audit logs, secure storage of personal data. This is my main profile — I work daily with FastAPI / async SQLAlchemy / JWT / Docker.

What I will include in the implementation:
— Document upload via S3-compatible storage, access to files through signed URLs with TTL
— Decision engine with a clear state machine: pending → approve / reject / re-request. Each transition is logged: actor, timestamp, reason
— REST API for integrations with external services (including webhook notifications to providers upon status change)
— Security: JWT with roles, encryption at rest for personal data, masking of personal data in logs
— Complete audit log of each action (requirement from the technical specifications), indexed for quick retrieval
— Lightweight admin layer on FastAPI for manual moderation: filters, status change, application history viewing
— Docker + Alembic migrations + pytest-asyncio + CI-ready configuration

Timeline breakdown (14 days with full access from day one):
— 3 days: architecture + database schema + basic model + Alembic
— 5 days: REST API + decision engine + integration points
— 3 days: admin layer + audit log
— 3 days: tests + documentation + final stabilization

Question before starting: is document verification purely manual (admin visually checks the uploaded documents), or are we planning to integrate with an external KYC provider (Diia.Signature, Jumio, Sumsub, Onfido)? This affects the format of the 9th workstream and the distribution of hours.

I am ready to discuss the details. Expand

Budget: 27000 UAH Deadline: 1 day

Hello! We are the NovaCore Solutions team. We have deep expertise in developing CRM systems with multi-level access and automated workflows, so we will implement your verification platform with a focus on security and flexible decision-making logic. We will build the system on FastAPI/PostgreSQL, implement a secure document storage and logging of every action (Audit Log), and prepare a modular architecture for easy integration with KYC providers. We are ready to offer a database structure and an MVP development plan based on our experience in high-load SaaS projects.

Budget: 26990 UAH Deadline: 29 days

Good day!
My name is Valentin, and I represent Arctic Web Agency. We are a team that specializes in creating modern and effective solutions for business. I can provide examples of our similar work in personal messages. We are ready to take your project to work!

Sincerely,
Arctic Web Team
Freelancehunt

Budget: 27000 UAH Deadline: 10 days

Hello! I work with Python+Django, have experience with PostgreSQL, REST API, JWT, OAuth2, Docker, and I would like to offer several solutions to your task. Shall we discuss it in private?

Budget: 26997 UAH Deadline: 4 days

Good day! I am ready to complete this project. Extensive experience in developing various applications.

Budget: 27000 UAH Deadline: 14 days

I have familiarized myself with the task description. I understand that it involves the development of a full-fledged backend solution for KYC verification from scratch, taking into account scalability, security, and integrations.

I have basic experience working with the backend (API, working with databases, integrations), and I understand the principles of building REST APIs, authorization (JWT), and data processing logic.

I have not fully worked with KYC-level systems, but I understand the architecture:
— receiving and storing user data
— document processing
— decision-making logic
— integration with third-party services
— auditing and data storage

I can join the project as part of a team or on specific tasks, with a gradual immersion into the system.

Regarding cost and timelines: it depends on the scope of tasks and the role in the project.

I am ready to discuss the details and format of collaboration.

Thank you. Expand

Budget: 27000 UAH Deadline: 1 day

Good day!
I have experience in backend development in Python, including creating APIs, working with databases, authorization, storing user data, and building scalable server logic.
I have worked on developing systems with business logic for decision-making, integrations via REST API, logging actions, and preparing architecture for further expansion and connection of third-party services.
I suggest discussing the details, as well as the cost and deadlines in private messages.

Budget: 27000 UAH Deadline: 12 days

Greetings! I am a Fullstack developer (Python/Django + React/Next.js). I already have experience implementing systems with complex status logic (acceptance/rejection of applications), which I have successfully integrated into my past projects.

What I will do for you:
1. Backend: I will implement the entire KYC cycle (upload, verification, state changes) on Django.
2. Frontend: I will create a fast and user-friendly interface for users and an admin panel on React/Next.js.
3. Integrations: I will set up REST API, data storage in PostgreSQL, and Docker for deployment.

I have already solved similar tasks with the application lifecycle, so I will do everything quickly and technically correctly.

I am ready to discuss the technical specifications and get started. Write to me!

Budget: 27000 UAH Deadline: 7 days

Hello, Evgeny! I am Nina, the manager of the developer Valentin.

We have carefully studied the technical specifications. Building a user verification system from scratch is a task that is not just about code, but about architecture and data logic. Valentin has direct experience in designing fintech solutions, where security and automation are the top priorities.

Our solution for your KYC system:

FastAPI & Decision Engine: We will implement not just "statuses," but a flexible decision-making engine. The logic (Approve / Reject / Retry) will be modular, allowing you to easily change verification rules in the future without rewriting the entire backend.

Secure REST API: Full implementation of JWT/OAuth2 and encrypted document storage. We understand the criticality of personal data in KYC.

AI integration (optional): Since Valentin specializes in AI solutions, we can implement preliminary document checks through agents before they reach the administrator, saving you up to 70% of the time on manual moderation.

Scalability: We will package everything in Docker right away. The system will be ready for loads and integration with any external providers (Sumsub, Onfido, etc.) through clean interfaces.

Why choose us:
Valentin uses an AI-augmented development approach. This means you get architecture quality at the level of a Senior Architect, but with a development speed that is 2-3 times higher than standard due to the use of agent CLI tools.

Budget: 27,000 UAH.
Timeline: 7-10 days until the service is fully ready.

Evgeny, what type of documents are planned to be verified first? We would be happy to discuss the details and propose an optimal database structure.

Best regards,
Nina. Expand

Budget: 27000 UAH Deadline: 10 days

Hello! We are a small team that has been engaged in web development and building scalable microservices for over 4 years, so we are ready to implement your KYC verification system "turnkey". We will implement a decision engine (Approve/Reject/Pending), set up a basic administrator interface for manual verification, and ensure complete isolation of personal data according to best security practices. Our experience of over 4 years allows us to guarantee high code quality in Python and the system's readiness for high loads thanks to Docker infrastructure. Be sure to check our work samples that demonstrate a high level of technical expertise: freshagro.com.ua, farfieworldwide.com, rivnekolo.com.

Budget: 27000 UAH Deadline: 15 days

Good day! My colleague and I have been professionally engaged in the technical design of fintech solutions and the development of secure APIs for over 4 years, so we will help you create a reliable user verification service from scratch. We will implement frontend auditing (if an interface is provided) and backend logic on Django or FastAPI, set up an audit log for compliance with security standards, and ensure the service can operate offline with easy integration of third-party providers. We will ensure technical excellence in execution, including PostgreSQL optimization for handling large volumes of data; our experience is confirmed by successful projects: drkukharevich.rivne.ua, crave-agency.com.ua, jk-solution.com.ua.

Budget: 27000 UAH Deadline: 21 days

Hello! My partner (designer + full-stack) and I have been specializing for over 4 years in the development of high-load backend systems and the integration of AI services, so we will professionally implement your verification platform based on FastAPI. We will design the database architecture in Figma to visualize KYC data flows, ensuring technically flawless decision-making engine logic, secure document storage with encryption, and a flexible REST API for future integrations. Our experience of over 4 years allows us to implement JWT/OAuth2 authorization and Docker containerization for easy scaling; take a look at our work from the perspective of technical architecture and security: hyperfi.tech, espressolab.com.ua, hudi.com.ua.

Budget: 27000 UAH Deadline: 20 days

Hello! We from the SDEV team have experience in developing scalable backend solutions, including user verification systems. Our approach will ensure secure storage of personal data, create decision-making logic (approval/denial/additional requests), and set up integration with third-party services.

We will use Python (FastAPI or Django), PostgreSQL/MySQL, and JWT/OAuth2 technologies for handling authentication, as well as Docker for scaling. The system will include a REST API, an administrative interface with an audit log, and the ability to extend functionality.

We will pay special attention to document processing, images, and photo verification to ensure a high level of reliability. More about our competencies can be found in the [SDEV portfolio](https://s-dev.tech/freelance).

Budget: 27000 UAH Deadline: 16 days

Hello.

I have solid backend experience with Python/FastAPI, PostgreSQL, REST APIs, secure data flows, and production-ready service architecture. This project is clear to me: build a scalable user verification system with document/selfie handling, decision workflow, secure storage, audit logging, admin-side controls, and readiness for future third-party provider integrations.

I can approach this as a proper backend service, not just a quick prototype:

* clean API architecture
* secure handling of sensitive user data
* verification workflow with approve / reject / re-request logic
* audit trail and admin functionality
* scalable structure for future integrations

I work with backend systems where security, maintainability, and extensibility matter. Ready to discuss the exact scope and split implementation into clear milestones if needed. Expand

Budget: 27000 UAH Deadline: 14 days

Hello! 🚀

I have experience in developing backend systems with complex business logic, data processing, AI/API integrations, and secure solutions**, including work with validations, auditing, and access roles.

Recommended tech stack:

Backend: Python (FastAPI or Django), PostgreSQL
Security: JWT / OAuth2, data encryption, access isolation
Integrations: KYC API (if needed), photo/document processing, webhooks
Infrastructure:** Docker, scalable architecture, logging and auditing

What I will implement:
— KYC flow (upload → processing → decision)
— decision-making engine (approve / reject / re-check)
— REST API for integrations
— secure storage of personal data
— audit log + basic admin panel

I am ready to design and implement the system as a scalable service that is easy to expand and integrate in the future.

Best regards,
Andriy Expand

Budget: 26543 UAH Deadline: 12 days

I have solid experience building backend systems and can develop a scalable KYC verification service from scratch. I’ll design a secure flow for document upload, selfie processing, and decision logic (approve/reject/re-request), with a clean REST API for integrations.

I’ll ensure proper data protection (encryption, access control), audit logging, and a simple admin panel. The architecture will be modular, allowing easy integration with third-party providers or running as a standalone solution.

Tech: Python (FastAPI/Django), PostgreSQL/MySQL, JWT/OAuth2, Docker.

Happy to clarify requirements and suggest the best architecture.

Budget: 27000 UAH Deadline: 30 days

Good day
My name is Dmytro, I represent the company King Kong Lab
We have experience in developing backend systems from scratch, including data processing services, APIs, and decision-making logic. Your case is clear — it is a KYC service with a focus on security, scalability, and integration capabilities.
Regarding the approach:
we build the backend on FastAPI or Django (depending on the tasks)
we design a modular architecture for future integrations
we implement the KYC process: document uploads, photo/selfie processing, verification statuses
we add a decision engine (approve / reject / retry)
we create a REST API for external integrations
we set up secure data storage (encryption, access controls)
we implement an audit log and a basic admin panel
We work with:
Python (FastAPI / Django)
PostgreSQL / MySQL
JWT / OAuth2
Docker
We can immediately incorporate the possibility of connecting third-party KYC providers or keep the system autonomous.
We are ready to break the development into stages and start with an MVP (basic verification + API + decision logic), then scale up.
I would be happy to discuss the details and propose an optimal architecture.
I look forward to collaborating. Expand

Budget: 27000 UAH Deadline: 10 days

Ready to start working on the project, we can discuss the details in private messages.

Budget: 27000 UAH Deadline: 21 days

I have worked and am working with a similar technology stack, overall the task is clear.

Budget: 27000 UAH Deadline: 5 days

Hello, I have the necessary experience with the stack, and I have also worked in fintech, so I can do everything in the best way.
My GitHub: https://github.com/onyx144

Budget: 27000 UAH Deadline: 21 days

Hello,

I’m a backend developer with 4+ years of experience in Python using FastAPI and Django. I build scalable systems from scratch with a focus on reliability, security, and clean architecture.

I have solid experience with REST APIs, JWT and OAuth2 authentication, third-party integrations, and webhook-based systems. I’ve worked extensively with PostgreSQL, Redis, and background processing to handle high-load workflows and ensure стабильность в production.

For your project, I can design and implement a full KYC-style verification flow including document upload, processing, and a decision engine for approve, reject, or re-request. I will also set up secure data storage, audit logging, and a simple admin interface. The system will be built in a modular way so it can easily integrate with external providers like Sumsub or Onfido, or run as a standalone solution.

I can start immediately and would be glad to discuss your requirements in more detail.

Budget: 27000 UAH Deadline: 3 days

Hello! I have studied your project and am ready to start working immediately. I guarantee excellent quality and promptness.

Budget: 27000 UAH Deadline: 1 day

Hello, write to me in private to discuss the details. I will be happy to help you!