Ship one production-ready backend or AI feature without adding another long hiring process.

Spring Boot • REST APIs • AI/LLM Integrations • PostgreSQL • Auth & RBAC • Docker • SaaS

I build focused backend and AI features for SaaS products that need to move from requirement to production-ready implementation quickly. This service is for founders, product teams, and software agencies that already know the feature they need and want an engineer to own a clearly bounded implementation.

WHAT I CAN BUILD

• Spring Boot REST APIs • AI/LLM API integrations with OpenAI, Gemini, or Groq • SaaS backend functionality and PostgreSQL-backed workflows • Authentication, JWT, and role-based access control (RBAC) • Third-party API integrations • Backend-to-frontend integrations • Docker and deployment-related backend fixes • API validation, error handling, logging, and production hardening • Bounded RAG or document-chat modules where the scope fits this sprint

THE $300 STARTER SPRINT

The fixed price covers ONE agreed, clearly scoped feature, such as one small REST API endpoint or enhancement, one third-party or AI provider integration, one contained backend workflow, one authentication/RBAC improvement, one backend bug with a defined outcome, one Docker/deployment fix, or one small AI-enabled SaaS feature.

DELIVERABLES

Production-ready backend feature One agreed backend, API, or AI feature.

Integration and business logic Required API, database, provider, or application logic within the agreed scope.

Reliability basics Validation, sensible error handling, and logging appropriate to the feature.

Testing Relevant tests for the agreed implementation where practical.

Deployment-ready handoff Configuration notes, environment-variable requirements, and concise implementation documentation.

Source-code handoff Clean implementation integrated into the agreed repository/codebase or delivered as the agreed module.

Up to 2 reasonable revisions are included within the originally agreed scope.

PROCESS

Step 1 — Scope You send the feature requirement, current stack/codebase context, and acceptance criteria.

Step 2 — Technical review I confirm the approach, dependencies, risks, and exact sprint boundary.

Step 3 — Build I implement the backend, API, or AI functionality with concise progress communication.

Step 4 — Test I validate the agreed acceptance criteria and relevant failure cases.

Step 5 — Handoff You receive the implementation, configuration/documentation, and a concise technical handoff.

CLIENT REQUIREMENTS

Please provide: • The feature requirement and what must work at completion • Your current backend, frontend, database, hosting, and relevant services • Whether this is an existing codebase or a new module • Exact acceptance criteria • Relevant external API documentation • Required credentials only after the project begins and through an appropriate secure method

Do not send production secrets, passwords, or private API keys inside the public project description.

PROVEN THROUGH A PRODUCTION-ORIENTED AI PLATFORM

I built Dervale, a multi-tenant AI gateway and control plane using Java, Spring Boot, React, PostgreSQL, Redis, and Docker.

Dervale includes multi-provider AI integrations and routing, authentication and RBAC, API and gateway keys, policy controls, usage governance, rate limits and budgets, request and audit logging, usage analytics, AI chat workflows, and production deployment.

That systems experience helps me build AI integrations as maintainable product infrastructure—not isolated glue code.

Portfolio: https://harmanpreet-portfolio-delta.vercel.app GitHub: https://github.com/harmanpreetbuilds

BEST FIT FOR

• SaaS founders and technical founders • AI startups • Software agencies and product studios • CTOs with an engineering backlog • Teams adding AI functionality to an existing product • Agencies needing temporary backend capacity

SCOPE BOUNDARY

The $300 sprint does not include a complete SaaS or mobile application, a full frontend redesign, a large migration, an enterprise architecture rebuild, unlimited endpoints or revisions, a complex cloud infrastructure rebuild, or a multi-week engineering project.

Larger requirements can be broken into clear milestones and quoted separately.

Send me the backend feature, integration, or backlog item you want shipped. I’ll confirm whether it fits the sprint and flag any scope or architecture risks before we begin.