Principal Full-stack Engineer

Helium Technology

You will architect end-to-end systems, mentor engineers, and drive AI innovation in ambiguous environments.

Compensation:

USD 6K - 9K/month

Location:

Remote: India

Mission of Helium Technology:

"Whether you are a startup, a growing mid stage company, or a large financial institution, our team has the experience to deliver comprehensive lending solutions."

What makes you a strong candidate:

• You have +8 years experience in React.js, Python, PostgreSQL, Full-stack development.
• You are proficient in Software architecture, Security, Optical character recognition (OCR), Next.js, FastAPI, Document processing.
• English - Conversational

Responsibilities and more:

As a Principal Full-Stack Engineer, you will be a technical owner rather than a task executor. You will design systems end to end, make architectural trade-offs, and raise the engineering bar across backend, frontend, and AI-driven workflows.

This is a hands-on role for someone who enjoys owning complex problems, mentoring other engineers, and shipping production systems in ambiguous environments.

Core Responsibilities

Technical Leadership and Architecture

* Own the architecture and technical direction of major systems, including APIs, data pipelines, AI agents, and frontend surfaces.

* Design scalable and fault-tolerant systems for document ingestion, extraction, and compliance workflows.

* Make pragmatic trade-offs between speed, correctness, cost, and long-term maintainability.

* Act as a technical decision maker, not only an implementer.

Backend and Systems

* Build and evolve backend services using Python with FastAPI and asynchronous workflows.

* Design and maintain PostgreSQL schemas, including performance tuning, migrations, and data modeling.

* Work with background workers such as Celery and Redis, or equivalent, for long-running and asynchronous tasks.

* Implement robust observability through logging, metrics, tracing, and production debugging.

AI and LLM-Driven Workflows

* Design and implement LLM-powered agents for document extraction, classification, and compliance checks.

* Work with structured outputs such as JSON schemas, prompt design, retries, and failure handling.

* Build guardrails to reduce hallucinations and ensure deterministic outputs when required.

* Integrate with modern LLM stacks such as OpenAI, Gemini, Claude, and LangChain-style orchestration.

Frontend and Product Surfaces

* Build and own user-facing experiences using React and Next.js.

* Translate complex backend workflows into clear and intuitive user interfaces.

* Partner closely with product and design teams to ship fast and usable features.

* Maintain frontend quality, performance, and developer ergonomics.

Security, Reliability, and Quality

* Enforce best practices related to authentication, permissions, MFA, and data security.

* Improve system reliability through error handling, retries, idempotency, and testing.

* Review critical pull requests and raise overall code quality across the team.

* Participate actively in incident response, including debugging, mitigation, and prevention.

Mentorship and Team Impact

* Mentor mid-level and senior engineers through design reviews and pairing.

* Set engineering standards and lead by example.

* Help evaluate and onboard future engineers.

* Act as a multiplier for the team rather than a bottleneck.

Requirements

Must-Have

* Eight or more years of professional software engineering experience.

* Strong hands-on experience with Python using FastAPI or similar frameworks.

* Strong hands-on experience with React and modern frontend frameworks.

* Strong hands-on experience with PostgreSQL, including schema design, indexing, and performance optimization.

* Proven experience designing and owning production systems end to end.

* Comfort working in ambiguous and fast-moving startup environments.

* Excellent debugging and problem-solving skills.

* Ability to clearly communicate technical decisions to engineers and founders.

Strongly Preferred

* Experience with asynchronous systems, background jobs, and queues.

* Prior experience with document processing, PDFs, OCR, or data extraction pipelines.

* Experience building or integrating AI and LLM-based systems in production.

* Familiarity with cloud infrastructure such as AWS or GCP, Docker, and CI/CD pipelines.

* Experience working directly with product and business stakeholders.

Nice-to-Have

* Experience in insurance, fintech, or other regulated industries.

* Exposure to observability tools such as Sentry, PostHog, or OpenTelemetry.

* Experience scaling early-stage systems without over-engineering.