Senior Backend Engineer - Payments & Fintech (India, Chennai)

About GoCharting GoCharting is a web-native charting and trading workflow platform with institutional-grade orderflow and DOM tools footprint/cluster charts, volume/market profile, cumulative delta, imbalance charts, DOM trading. We are the only platform that delivers these capabilities fully on the web. Comparable to TradingView for general charting, but differentiated as the leader in the professional orderflow niche. PE-acquired and funded in 2025, profitable, 3M+ registered traders globally, with a mandate to scale 10x over 4 years. The Role This is the most consequential backend role we are hiring this year. GoCharting runs a freemium subscription business across two payment gateways (Stripe and Razorpay), two legal entities (US and India), and multiple currencies and the systems that move money, grant entitlements, and report revenue have grown organically to the point where they need to be rebuilt properly. Subscriptions and resubscriptions don't always renew cleanly, some captured payments never become entitlements, refunds and disputes aren't fully handled, and the data we need for exchange reporting, accounting close, and conversion/retention analysis has to be reconstructed by hand. You will own the fix. Working from an existing target design a journals-as-truth billing and entitlement ledger you will build the canonical payments, subscription, entitlement, and user-billing platform from the ground up and migrate the live business onto it without dropping a rupee or a dollar. This is the financial heartbeat of the company: no payment is correct, no entitlement is granted, and no month closes cleanly without the system you build. You report to the CTO inside Core Platform Engineering and work in lockstep with Finance and the COO, who own the design and the accounting/reporting requirements. In year one, success looks like: every captured payment producing exactly one ledger entry and the right entitlement; subscriptions and resubscriptions renewing, upgrading, and lapsing correctly across both gateways; refunds, disputes, and proration handled in code; and clean, trustworthy data flowing to accounting, exchange reporting, and the growth team with the legacy account model retired behind the new one. What you'll do Build the canonical billing & entitlement ledger design and implement an append-only, journals-as-truth Postgres schema (orders, signed payments ledger, dated entitlement grants, gap-free per-entity invoice numbering) where all state is a derived view and every entitlement traces to a paid order lineOwn the full subscription lifecycle in code purchase, renewal, resubscription, upgrade/downgrade/switch, proration, trials, cancellation, and lapse across both Stripe and Razorpay, ending the renewal/resubscription bugs that lose money and entitlements todayBuild the gateway ingest pipeline idempotent, replay-safe webhook handling for Stripe, Razorpay, and Apple notifications, normalized into the ledger with dead-letter handling and reconciliation that proves the gateway and our books agree every dayHandle the hard money paths refunds, chargebacks/disputes, credits, and partial/zero-amount settlements, with signed lines that allocate the gateway-charged amount correctly and never double-countProduce clean financial & entitlement data the views that feed accounting close (revenue recognition, multi-entity GST/IGST and US tax, deferred revenue), exchange reporting (CME and Indian exchanges), and conversion/retention analyticsOwn the user billing surface end-to-end the user cabinet and checkout (TypeScript/Astro/React) where customers buy, upgrade, manage, and cancel so the experience and the ledger never disagreeMigrate the live business safely backfill historical payments with documented confidence tiers, run the new system in parallel against the legacy CouchDB account model, prove reconciliation is clean, then cut over read and write paths region by region What we're looking for Must-haves: 610 years backend engineering, with deep Go and strong relational data-modelling and SQL you design schemas that stay correct under concurrency and scaleYou have built or rebuilt payments, subscriptions, and ledgers end-to-end payment-gateway integration, idempotent webhooks, the subscription lifecycle (renewals, proration, upgrades, cancellation, dunning), and refunds and disputes this is the core of the job, not an adjacent skillThe full money-systems depth that surrounds a ledger is required, not optional: reconciliation (gateway books), revenue recognition and tax (e.g. GST/IGST, ASC 606 or equivalent), financial/exchange reporting, and event-sourced / append-only ledger design (journals-as-truth, derived state, signed entries)Experience building or owning a B2B product where billing and entitlement complexity is real (metering, plans/add-ons, multi-tenant or partner billing) GoCharting also runs a /b2b and white-label About GoCh