Senior Backend Technical Lead - Python / FastAPI

Kato Butler India; Bengaluru; On-site; INR 2,000,000 - 3,000,000; Full time

Job summary

Kato Butler India seeks a hands-on Senior Backend Technical Lead in Bengaluru to own the backend platform, APIs, and database architecture. This role combines technical leadership with active coding in Python and FastAPI, reviewing architecture decisions and ensuring production-quality code reaches protected branches.

You will design REST APIs, OpenAPI specs, and RBAC systems, review PRs including AI-generated code, and oversee PostgreSQL schemas, Redis-based processing, and robust CI/CD

Qualifications

• Hands-on senior backend engineer with expertise in Python/FastAPI and API design.
• Experience in multi-tenant SaaS, RBAC and security best practices.
• Ability to review AI-generated code and ensure production-grade quality.

Responsibilities

• Own backend engineering quality and standards.
• Lead backend development in Python and FastAPI; contribute code when needed.
• Design and review REST APIs; maintain OpenAPI specifications and Swagger docs.
• Review PRs including AI-generated backend code; ensure correct tenant isolation.
• Design PostgreSQL schemas, queries, migrations; optimize performance.
• Ensure asynchronous processing infrastructure with Redis, background jobs, and CI/CD.

Skills

Python

FastAPI

REST APIs

OpenAPI

Swagger

Async Python

API security

Tools

PostgreSQL

Redis

Docker

Kubernetes

Terraform

Celery

Job description

ROLE OVERVIEW

Work location: our development office at Four Seasons Private Residences, Embassy One, 8 Bellary Road, Ganganagar, Bengaluru 560032 (Hebbal / Mekhri Circle). Full-time on-site. The address listed on our company profile is our registered office.

We are looking for a highly experienced Senior Backend Technical Lead to take daily technical ownership of our backend platform, APIs, database architecture and backend engineering quality.

This is a hands‑on technical leadership role, not a management‑only position. You will lead backend implementation, review pull requests, work with AI coding agents, validate architecture decisions and make sure only production‑quality code reaches protected development branches.

The focus is backend and platform engineering. You must also know React, Next.js and TypeScript well enough to review frontend/backend contracts and understand features end to end.

Role & responsibilities

• - Own backend engineering quality and technical standards.
• - Lead backend development in Python and FastAPI; participate directly in coding whenever required.
• - Design and review REST APIs; define and maintain OpenAPI specifications and Swagger documentation.
• - Review pull requests before merge, including reviewing and correcting AI‑generated backend code.
• - Design and review PostgreSQL schemas, queries and migrations.
• - Enforce strict tenant isolation across the platform.
• - Design authentication and authorization systems; implement and review RBAC and permission models.
• - Design reliable integrations with third‑party services.
• - Define asynchronous processing and background‑job architecture; review Redis caching and distributed state strategies.
• - Ensure correct transaction handling, concurrency and idempotency; identify race conditions and data‑consistency issues.
• - Improve automated testing and CI/CD quality gates; review backend and API security.
• - Review infrastructure‑related backend decisions and diagnose complex production issues.
• - Mentor backend and junior developers; work closely with the Solution / Platform Architect and translate architecture decisions into production‑ready implementations.

Preferred candidate profile

PYTHON / FASTAPI - STRONG EXPERTISE REQUIRED

Python 3.11+, FastAPI, async Python, Pydantic, REST APIs, OpenAPI, Swagger, API versioning, dependency injection, middleware, background processing, error handling, structured API responses, API security.

POSTGRESQL & DATA

PostgreSQL, SQL, database modelling, relational schema design, migrations, indexing, query optimisation, transactions, locking, concurrency, connection pooling, data integrity, replication concepts, backup and recovery. PostGIS, pgvector and PgBouncer are an advantage.

REDIS / BACKGROUND PROCESSING

Redis, caching strategies, distributed locks, background jobs, queues, scheduled jobs, retries, failure handling, idempotent processing. Celery or an equivalent distributed task system is strongly preferred.

AUTHENTICATION & SECURITY

OAuth2, OpenID Connect, JWT, RBAC, IAM concepts, MFA concepts, session management, API authentication and authorization, tenant isolation, secrets management, secure API design. You must understand the security risks of multi‑tenant SaaS platforms and distributed applications.

MULTI‑TENANT ARCHITECTURE

Multi‑tenant SaaS applications, tenant isolation, tenant‑aware database queries, permission and authorization boundaries, preventing cross‑tenant data leakage, scalable tenant architecture.

INFRASTRUCTURE & DEPLOYMENT

Docker, Docker Compose, Linux, Git, GitHub, GitHub pull‑request workflows, GitHub Actions, CI/CD, Terraform / Infrastructure as Code, Kamal deployment, AWS or equivalent cloud, compute infrastructure, load balancers, reverse proxies, networking fundamentals, S3‑compatible object storage, CDN architecture, Cloudflare, environment and secrets management. You should understand high availability, zero‑downtime deployments, rollback strategies, multi‑region concepts, disaster recovery, horizontal scaling and production monitoring.

OBSERVABILITY & PRODUCTION OPERATIONS

Structured logging, application monitoring, metrics, tracing, alerting, health checks, production debugging, incident investigation, performance profiling.

FRONTEND KNOWLEDGE - REQUIRED BUT SECONDARY

Working knowledge of React, Next.js, TypeScript, Tailwind CSS, frontend/backend API integration, authentication flows, server and client components, frontend state and data‑fetching patterns. You do not need to be the primary frontend developer, but you must be able to review frontend/backend contracts and understand features end to end.

AI‑ASSISTED ENGINEERING

AI is a core part of our engineering workflow. You should be comfortable with AI coding agents, AI‑assisted development, reviewing AI‑generated code, automated PR review, AI‑generated tests, giving coding agents precise technical instructions, validating AI implementations rather than trusting them, correcting unsafe AI‑generated code, and defining engineering rules that AI agents must follow. Strong engineering judgement matters more than experience with any specific AI product.

STRONG ADVANTAGE

Kubernetes, WebSockets, realtime systems, WebRTC, SIP, VoIP, FreeSWITCH, event‑driven architecture, messaging systems, pgvector, PostGIS, Supabase, high‑volume APIs, payment integrations, travel APIs, messaging platforms, AI / LLM integrations.

WHAT WE ARE LOOKING FOR

A genuinely hands‑on senior backend engineer who can lead technically. You should be able to open a pull request and spot incorrect tenant isolation, unsafe database transactions, race conditions, missing idempotency, poorly designed APIs, incorrect async logic, security vulnerabilities, inefficient SQL, poor database modelling, incorrect Redis usage, unnecessary coupling, missing tests, unsafe migrations, scaling bottlenecks, fragile deployment patterns and architecture that will become hard to maintain.

You should understand a feature end to end: React / Next.js -> REST API -> FastAPI -> business logic -> PostgreSQL / Redis -> infrastructure.

The role requires strong backend engineering judgement, ownership, technical leadership and the ability to keep a fast‑moving AI‑assisted development team technically disciplined.