Principal Engineer (frontend)

Sage City; Bengaluru; Hybrid; INR 4,200,000 - 6,500,000; Full time

Job summary

Sage is seeking a Principal Front-end Engineer in Bengaluru to lead the frontend architecture and deliver a high-quality SaaS solution. You will drive technical strategy, design systems, and mentor engineers, ensuring robust, scalable client-side code.

You will collaborate with product, backend, and design teams in a hybrid model (3 days in office) and participate in building performant, accessible UI using TypeScript, React, and modern tooling.

Qualifications

• 10+ years of frontend engineering experience.
• Strong English communication skills.
• Ability to lead technical decisions and mentor engineers.

Responsibilities

• Define frontend best practices, coding standards and design systems.
• Act as final reviewer for critical frontend design and implementation decisions.
• Mentor engineers and foster a culture of technical excellence.
• Break down initiatives into milestones and deliver high-quality features with minimal oversight.
• Collaborate with Product, Backend and Support teams for maintainable delivery.

Skills

TypeScript

React

JavaScript

HTML5

CSS3

Redux Toolkit

XState

TanStack Query

Tailwind CSS

MUI

styled-components/Emotion

ESLint/Prettier

Vite

Webpack/Rollup

Nx (monorepo)

REST APIs

JWT/OAuth2

ARIA accessibility

Vitest/Jest

Testing Library

Tools

Nx monorepo

Vite

Webpack/Rollup

Job description

Job Description About the RoleAs a Principal Front-end Engineer at Sage, you will provide technical leadership in designing, developing, and delivering a high-quality SaaS solution that exceeds customer and business partner expectations. We are looking for someone with 10+ years of professional experience in frontend engineering, who can bring technical depth, architectural vision, and leadership maturity to the team. Proficiency in English, written and verbal, is required.We value humility and collaboration. We are looking for people who can work as part of a team, not in silos. We expect engineers to take ownership beyond just writing code, including tests, documentation, and long-term code quality.Location: Bangalore, India. This is a hybrid role, three days per week in the office.Required SkillsCore languages & frameworks Strong TypeScript (strict) and modern JavaScript (ES Modules, async). Deep React experience (hooks, composition, performance); React 19 / React Compiler a plus. Solid HTML5, CSS3, and responsive/accessible UI fundamentals.Build & tooling Modern build tooling Vite (or Webpack/Rollup); code splitting and bundle optimization. Git and pull-request workflows; monorepo experience (Nx) a plus. Linters/formatters (Biome, ESLint/Prettier) and CI discipline.State & data State management with Redux Toolkit, XState (state machines), and/or TanStack Query. RxJS / reactive streams. Consuming REST APIs; JWT/OAuth2 bearer auth on the client; robust error handling.Styling & design systems Tailwind CSS, MUI (Material UI), styled-components/Emotion. Working with a design-token system for brand consistency.Data grids & performance Complex data grids (ag-Grid Enterprise preferred, or TanStack Table/Handsontable): virtualization, server-side row model, custom renderers/editors. Frontend performance profiling and optimization (rendering, memoization, main-thread work). Web Workers for off-main-thread compute.Accessibility & i18n WCAG 2.1/2.2 AA accessibility practices; ARIA, keyboard, focus management. Internationalization (i18next or similar), including locale-aware date/number formatting.Testing & quality Unit/component testing (Vitest/Jest + Testing Library), API mocking (MSW), and Playwright E2E. Secure client-side coding against the OWASP Top 10 (XSS, token handling, safe storage).AI Tooling Productive use of AI-assisted developer tooling (e.g. GitHub Copilot, Claude Code, Cursor) to accelerate day-to-day frontend development. Building AI-assisted / generative-AI UX: in-app copilots, natural-language querying, or smart suggestions surfaced to the user. Integrating LLM APIs on the client (e.g. OpenAI, Anthropic, AWS Bedrock) with streaming/token-by-token rendering, cancellation, and graceful error/loading states.Nice to Have Web Crypto / AES-GCM application-level encryption and client-side key management. Lexical (or ProseMirror/Slate) rich-text/formula editors; grammar parsing (ohm-js). Dependency-graph / DAG modeling (graphlib/graphology). CRDT / operational-transform real-time collaboration. Storybook and visual regression testing. New Relic browser RUM, Pendo, and web-vitals (INP/FPS) instrumentation. Experience meeting enforced performance budgets and SLOs in CI. Domain knowledge in finance, ERP, FP&A, budgeting, or spreadsheet-like applications. Designing accessible, trustworthy AI interaction patterns, such as citations, confidence indicators, and human-in-the-loop review for sensitive outputs.#LI-RTKey Responsibilities Responsibilities Define and enforce frontend best practices, coding standards, and design systems. Act as a final reviewer for critical frontend design and implementation decisions. Mentor engineers, provide constructive feedback, and build a strong culture of technical excellence. Break down complex initiatives into milestones, estimate effectively, and deliver high-quality features with minimal oversight. Collaborate across Product, Backend, and Support teams to ensure smooth delivery and long-term maintainability. Growth mindset: you are curious, always learning, and open to feedback. Strong collaboration skills: you work well with peers and cross-functional partners, and you know great ideas can come from anywhere.#LI-RT