Sarath Sasi

Native Swift on the device, Go on the wire.

role
Senior software engineer, iOS tech lead
based
Doha, Qatar
open to
Open to senior and lead roles across the Gulf, and remote.

I architect and ship systems that span both ends: iOS applications in Swift, and the Go platforms they talk to. Government, payments, real-time voice, automotive. The work that cannot quietly fail.

actor SarathSasi: Engineer {    let based = "Doha, Qatar"    let domains = [.government, .payments, .voice]    @MainActor    func build(_ idea: Idea) async throws -> Shipped {        try await idea            .architect(using: .clean)            .harden(with: .oidc)            .ship(to: .production)    }}

What I work on

iOS

Swift, SwiftUI, UIKit, Objective-C, Combine, SwiftData, Core Data

Swift Concurrency throughout — async/await, actors, @MainActor, structured cancellation. Multi-module codebases behind XCFrameworks so features ship independently.

Backend

Go, Chi, Echo, PostgreSQL, pgx, Redis, OpenAPI

Multi-tenant services with JSONB configuration, feature flags, and migrations packaged into a single deployable binary.

Real-time

WebRTC, LiveKit, QUIC/WebTransport, WebSocket, NATS JetStream, Opus

Push-to-talk voice: floor control, multi-channel, priority interruption, recording. SFU architecture with graceful transport fallback.

Web

SvelteKit, Svelte, TypeScript, Tailwind CSS, Angular

Operations consoles in English and Arabic with full right-to-left support, embedded alongside the Go API.

Identity

OAuth2, OIDC, PKCE, JWT/JWKS, RBAC, Keycloak, OpenFGA

Authorization Code with PKCE, RS256 validation through JWKS, HttpOnly cookies, silent refresh, fail-closed authorization.

Security

Signal Protocol, Keychain, NanoMDM, ADEP, Apple Business Manager

End-to-end encrypted messaging and in-house device policy enforcement, built to keep data in country.

Hardware

BLE, NFC, EMV, Ingenico, UART

Worldpay-certified card-present flows over Bluetooth to a physical terminal.

Infrastructure

Docker, Kubernetes, Helm, ArgoCD, Nginx, GitHub Actions, OpenTelemetry

Trunk based, automated, release on merge. Health and readiness probes, runbooks, handover documentation.

Selected work

Architecture

  • Go
  • LiveKit
  • WebRTC
  • QUIC
  • NATS

Push-to-talk platform, next generation

A field-operations voice platform was running its audio over a TCP message broker. I audited the existing eight-component estate — Go, Android, Angular, more than a hundred endpoints — and designed the replacement.

  • Evaluated the real options head to head: LiveKit against Mumble, NATS against RabbitMQ, SeaweedFS against MinIO.
  • Specified the migration to a WebRTC SFU on LiveKit, with QUIC/WebTransport primary and WebSocket fallback.
  • Wrote the specifications for floor control, multi-channel PTT, priority interruption, secure sessions, and voice recording.
  • Consolidated several backend services into one coherent platform architecture.

Platform

  • Go
  • Chi
  • PostgreSQL
  • SvelteKit
  • TypeScript

Multi-tenant control plane

Isolated tenant stacks with a central control plane that holds policy and metadata but never reaches into tenant business data. The separation is the point: a compromised control plane still cannot read a tenant.

  • Tenant lifecycle management with validated JSONB configuration, feature flags, and branding.
  • A slug-scoped pull API so tenant environments fetch their own staged users — the control plane never dials into a tenant network.
  • Manual and bulk CSV user staging workflows.
  • Bilingual English and Arabic operations console with full RTL, shipped as one binary with the API and its migrations.

iOS

  • Swift
  • SwiftUI
  • Signal Protocol
  • NanoMDM

Secure government messaging

A high-security internal messaging platform forked from Signal, carried from mobile architecture through enterprise distribution. Identity is username-only, so the directory never holds a phone number.

  • Built the organisation’s own MDM on NanoMDM, replacing a third-party vendor and keeping device data in country.
  • Took the organisation through its first Apple Developer Enterprise Program and Apple Business Manager setup.
  • Modular XCFramework build with Clean Architecture throughout.
  • Produced the architecture documents, deployment guides, and handover material the security and IT teams work from.

SDK

  • Swift
  • XCFrameworks
  • BLE
  • EMV
  • NFC

Card-present payments SDK

A point-of-sale SDK packaged as XCFrameworks and dynamic frameworks, so partner apps could take card payments without pulling in the whole stack.

  • Passed Worldpay certification at full compliance.
  • Drove the Ingenico Moby5500 terminal over BLE for EMV chip and NFC tap.
  • Kept the payment path non-blocking and thread-safe with async/await.
  • Lifted UI responsiveness by a quarter and cut crash rates on two shipped apps.

Where I’ve been

2025now

Senior software engineer, iOS tech lead

Government organisation, Qatar

Architecture and delivery across secure mobile, real-time communications, and multi-tenant platforms. Also co-built the Android push-to-talk proof of concept in Kotlin and Jetpack Compose.

20232025

Lead iOS engineer

ThoughtFocus

Payments SDK architecture and certification. Mentored the junior engineers; production defects fell by forty percent.

20212023

Senior iOS engineer

Concentrix Catalyst

Enterprise iPad applications on MVVMC and Combine. Stood up the test suites and wired them into CI.

20192021

Application development senior analyst

Accenture

Native and hybrid iOS for international clients. Native plugins that cut hybrid build times materially.

20152019

iOS application developer

Spurtree Technologies

First iOS years. Shipped end to end for BMW Group and others — BLE, UART, and analogue signal work against real automotive hardware.

2014

Master of Computer Applications

AMC Engineering College, Visvesvaraya Technological University

Get in touch

email
sarathspkum@gmail.com
phone
+974 5038 1132
github
sarathdev
linkedin
sarath-sasi-ios