Senior Backend Engineer

Untie-it; Rajkot; On-site; INR 250,000 - 420,000; Full time

Job summary

Untie-it is seeking a hands-on Senior Backend Engineer to own production backend systems. You will guide a small team, design and scale APIs, and integrate LLM-driven features with a focus on engineering depth over language.

You will work across Python or Node.js stacks (Django/FastAPI or Express/NestJS), own ADRs, and collaborate with stakeholders to deliver robust, cost-aware solutions on AWS.

Qualifications

• 4+ years of backend engineering in Python or Node.js beneath the framework.
• Framework experience (Django/FastAPI or Express/NestJS) is expected; framework-only experience is not enough.
• Production API experience — design, versioning, security, and debugging slow endpoints with evidence.
• Technical leadership — break a user story into tasks, document ADRs/runbooks, explain decisions.
• Scaling experience — know how to keep app up when DB or services scale.
• AWS fundamentals — Lambda, SQS/SNS/EventBridge, S3-driven workflows, IAM, cost awareness.
• LLM application experience — structured outputs, evaluation sets, handling non-determinism, cost as metric.
• AI-assisted development maturity — explain code merges with tools daily.

Responsibilities

• Own backend systems end-to-end: design, build, deploy, monitor, and scale.
• Architect and maintain APIs and data stores under load—with caching, parallelism, and cost in mind.
• Build and improve LLM-powered features: prompts, evaluation sets, accuracy, and API cost tracking.
• Document ADRs; design out single points of knowledge, not single points of failure.
• Guide a small team (4–6 developers): sprint planning, backlog refinement, tasking, code review, mentoring.
• Communicate estimates, trade-offs, timelines, and tough conversations with stakeholders.
• Run structured R&D: evaluate new tools with criteria, data-backed results, and written recommendations.

Skills

Backend engineering

Python

Node.js

AWS

LLM integrations

Technical leadership

Tools

Django

FastAPI

Express

NestJS

AWS Lambda

S3

SQS/SNS/EventBridge

Job description

We're hiring a hands-on Senior Backend Engineer to take ownership of production backend systems. Your primary language can be Python or Node.js — we care about engineering depth, not which syntax you think in.

This is a high-ownership seat: you'll make architecture decisions, scale live systems, integrate and evaluate LLMs in real products, guide a small development team, and communicate directly with stakeholders. There is no architect above you catching your mistakes — the judgment is the job.

We're looking for someone who understands their language beneath the framework, has scaled real systems on AWS, and treats LLMs as an engineering discipline — evaluations, structured outputs, cost control — rather than magic.

Key Responsibilities

Own backend systems end-to-end: design, build, deploy, monitor, and scale.

Architect and maintain APIs and data stores that hold up as load grows — parallelism, queuing, caching, and cost are your daily concerns.

Build and improve LLM-powered features: prompt/output contracts, evaluation sets, accuracy improvement, and API cost tracking.

Make and document architecture decisions (ADRs); design out single points of knowledge, not just single points of failure.

Guide delivery for a small team (4–6 developers): sprint planning, backlog refinement, breaking user stories into pickable tasks, code review, and mentoring.

Communicate directly with stakeholders: estimates, trade-offs, timelines, and the occasional hard conversation.

Run structured R&D: when asked to evaluate a new tool or approach, you return with clear criteria, results from real data, and a written recommendation.

Requirements

4+ years of backend engineering in Python or Node.js — genuinely, beneath the framework.

Framework experience (Django/FastAPI or Express/NestJS) is expected; framework-only experience is not enough.

Production API experience — design, versioning, security, and debugging slow endpoints with evidence rather than guesses.

Technical leadership — you can take a user story and break it into tasks a team can pick up, you document as you go (ADRs, runbooks) so knowledge never lives only in your head, and you can explain a technical decision to a non-technical audience and stand behind it.

Scaling scars — you've watched a database fall over before the app servers did, and you know what to do about it (and it isn't "upgrade the instance").

AWS fundamentals — Lambda and its real limits, SQS/SNS/EventBridge, S3-driven workflows, IAM, and cost awareness. You've been paged for something you built.

LLM application experience — structured outputs, evaluation sets, handling non-determinism, rate limits, and API cost as a first-class metric.

AI-assisted development maturity — you use modern coding tools daily and can explain every line you merge.

Nice to Have

Experience with both Python and Node.js.

Vector search experience.

GraphQL in production.

Frontend working knowledge.