Adarsh
Kumar

// Senior Staff Software Engineer

Relocating to the UK · Open to sponsorship
/**
 * I build the systems that move money — payment
 * rails, ledgers, and high-throughput core
 * infrastructure processing $15B+ annually.
 */
Download ResumeLinkedIn
10+
years_of_experience
500K+
users_served
$15B+
transactions_processed
5
countries
01. about_me.tsx

//About Me

/* A decade of building high-stakes systems at scale */

Adarsh Kumar

I build the systems that move money — payment rails, ledger systems, and high-throughput core infrastructure. Over the past decade I've engineered and scaled distributed platforms processing billions in transactions for 500K+ users across five highly regulated Southeast Asian markets.

My core expertise spans payment infrastructure and core banking (multi-bank routing with automated failover, real-time reconciliation, idempotency, and PCI-DSS-aligned systems), distributed systems and reliability (Kafka-driven event architectures sustaining 99.99% availability at 10K+ QPS), and regulated fintech and compliance (AML monitoring, transaction screening, and KYC pipelines built to central-bank standards).

I operate as a hands-on technical leader — defining the architecture, design contracts, and reliability patterns teams build upon while staying active on critical-path code. I'm now relocating to the UK (open to relocation and sponsorship) and open to Senior, Staff, and Principal Engineer roles in Payments, Fintech, and high-scale platform teams.

Led monolith-to-microservices migration for 500K+ users across 5 SEA markets with zero downtime

Built real-time payment routing processing $15B+ annually across 30+ channels in 3 countries

Co-founded and scaled a SaaS startup to $1.37M GMV with $480K in pre-seed funding

Founding engineer of a top-3 BSP-regulated crypto exchange in the Philippines

02. experience.tsx

//Experience

/* 10 years of building at the intersection of engineering and product */

StashAway

@ Kuala Lumpur, Malaysia

$ senior_staff_engineerApr 2024 – Present
  • ▸Decomposed a monolith serving 500K+ users across 5 SEA markets into 12+ microservices with Kafka event messaging — a zero-downtime migration that cut release cycles 40% and enabled 3x traffic spike handling during market volatility
  • ▸Own end-to-end deposit, cash-in, and withdrawal flows for 500K+ users across 5 SEA markets, with AML transaction monitoring, screening, and regulatory reporting aligned to each market’s central bank framework
  • ▸Consolidated KYC/auth from an 8-screen to a 4-screen flow with OAuth2 + MFA and parallelized background checks — signup time down 35%, conversions 10% over target
  • ▸Introduced MCP-based automated code review and test generation, clearing the senior-engineer PR review bottleneck — review turnaround down 50%, team shipping speed up 25%
  • ▸Defined and enforced API standards across 12+ services — versioned contracts, OpenAPI specs, consistent error handling, and pagination
  • ▸Built DR playbooks (DB failover, cross-region backup, graceful degradation) and established on-call rotations and incident reviews to drive down MTTR
  • ▸Cut AWS staging costs 30% (~$180K/year) via automated resource scheduling, right-sizing with Datadog utilization metrics, and Terraform cost tagging
  • ▸Mentored 8 engineers through architecture reviews, pair programming, and monthly tech talks while collaborating across product, compliance, and data teams in 5 markets
Node.jsReact NativeGoTemporalKafkaPostgreSQLMongoDBRedisAWSKubernetesDatadogSentry

Xendit

YC S15

@ Philippines, Indonesia & Malaysia

$ technical_leadSep 2022 – Feb 2024
$ senior_software_engineerFeb 2021 – Aug 2021
  • ▸Built a real-time payment routing engine with channel health scoring and automatic failover across 30+ bank and e-wallet integrations in 3 countries on $15B+/year volume — processing time 8s → 2.4s, success rate 88% → 97%
  • ▸Built a fault isolation layer with channel circuit breakers and graceful degradation during 10K+ QPS peaks — failed transactions down 250%, platform availability 99.99%
  • ▸Optimized 500M+ transaction records with S3 lifecycle tiering, DB indexes, and analytics read replicas — S3 costs down 65%, DB costs down 40%, p99 latency under 200ms
  • ▸Built a unified transactional notification service across WhatsApp, SMS, Viber, and email with an automatic fallback chain — 99.5% delivery across 10M+ monthly notifications
  • ▸Implemented payout retry and reconciliation using the outbox pattern and idempotency keys (PCI-DSS aligned) — zero lost or double-processed transactions even during partner bank outages
  • ▸Built real-time Datadog and Grafana dashboards for payment success rates, partner health, and circuit-breaker states — accelerating incident detection across all channels
  • ▸Core member of the Architecture Review Group — standardized cross-team engineering patterns and cut review turnaround 80% via templates and an async review process
  • ▸Led a 12-person engineering team and technical hiring; introduced TDD, code review standards, and sprint retros — delivery velocity up 35% over two quarters
Node.jsGoPostgreSQLMongoDBRedisKafkaAWSDatadogSentrySplunkDatabricksRedash

On Demand Deals

@ Pasig, Metro Manila, Philippines

$ co-founder_&_ctoAug 2021 – Sep 2022
  • ▸Co-founded a SaaS platform for F&B businesses and drove it from zero to product-market fit — owned end-to-end technical architecture, product direction, hiring, and delivery
  • ▸Built the entire platform solo initially (frontend, backend, infra, and deployment pipelines), then hired and managed a team of 4; transitioned from founder-led coding to scalable team execution without slowing delivery
  • ▸Closed $480K pre-seed from Iterative (YC for Southeast Asia) and Accelerating Asia; led the financial model, technical due diligence, and the investor narrative
  • ▸Scaled to 50+ shop locations across Manila in 6 months — $1.37M GMV with 200% month-over-month growth and minimal operational overhead
  • ▸Managed payment provider, POS integrator, and delivery partner integrations for order flow and settlement — reliable transaction processing and smooth merchant onboarding across third-party systems
ReactReact NativeNode.jsPostgreSQLAWSTerraformKafka

PDAX

@ BGC, Philippines

$ senior_software_engineerNov 2019 – Feb 2021
$ software_engineerMar 2018 – Oct 2019
  • ▸Founding engineer — joined pre-launch and co-architected the core system from zero to scale, helping grow PDAX into a top-3 BSP-regulated crypto exchange in the Philippines
  • ▸Built the core trade matching engine handling 5K+ concurrent orders at sub-100ms matching latency, designed for horizontal scaling during market volatility
  • ▸Integrated major Philippine banks (BDO, BPI, UnionBank) and e-wallets (GCash, PayMaya) for fiat deposits/withdrawals — settlement from 3 days to near real-time
  • ▸Designed and launched LOCQ — a first-of-its-kind blockchain-based fuel futures product enabling prepaid gas at locked on-chain prices, drawing a wave of non-crypto-native users
  • ▸Built internal wallet and ledger infrastructure with double-entry accounting across crypto and fiat — full auditability for BSP compliance and KYC/AML monitoring
  • ▸Built internal risk monitoring for suspicious activity, large withdrawals, and KYC workflows — enabling real-time automated detection and enforcement of compliance rules
  • ▸Optimized the trade engine and API layer with connection pooling, Redis query caching, and graceful degradation — 99.9%+ uptime during major market events
Node.jsPostgreSQLTimescaleDBRedisReact NativeSolidityAWSWeb3ERC20

Primus Software Corporation

@ Greater Noida, India

$ full_stack_developerSep 2017 – Jul 2018
  • ▸Built enterprise web and mobile applications for clients in healthcare, logistics, and education
  • ▸Led 3 pre-sales proof-of-concept projects end-to-end — scoped the approach, built demos in 2–3 weeks, and all three helped win new client contracts
  • ▸Owned frontend architecture and API design for a logistics tracking platform with a 5-person team; built reusable component libraries and set coding standards
ReactAngularNode.jsPostgreSQL
03. work_highlights.tsx

//Work Highlights

/* Selected projects that demonstrate scale, ownership, and impact */

~/projects/real-time-payment-routing-engine.md
$15B+/year processed

Real-time Payment Routing Engine

@ Xendit

Real-time routing engine with channel health scoring and automatic failover across 30+ bank and e-wallet integrations in 3 countries, on $15B+/year of payment volume.

// challenge

Manual routing meant if a bank channel went down, someone had to notice and switch traffic. Processing was slow and unreliable.

// impact
  • ▸Processing time reduced from 8s to 2.4s
  • ▸Success rate improved from 88% to 97%
  • ▸99.99% platform availability achieved
Node.jsKafkaRedisPostgreSQLDatadog
~/projects/platform-modernization.md
500K+ users, 5 markets

Platform Modernization

@ StashAway

Decomposed a monolithic system into 12+ microservices with clear API contracts and Kafka-based event messaging.

// challenge

A monolith serving 500K+ users across 5 SEA markets where one team's changes regularly broke another's features.

// impact
  • ▸Zero downtime during entire migration
  • ▸Release cycles reduced by 40%
  • ▸Platform handles 3x traffic spikes seamlessly
NestJSKafkaKubernetesTerraformAWS
~/projects/on-demand-deals.md
$1.37M GMV

On Demand Deals

@ Co-founded

Full-stack SaaS platform for the F&B industry — restaurants, cloud kitchens, and QSR chains across Manila.

// challenge

The Philippine F&B industry lacked a unified digital platform for order management, analytics, and growth.

// impact
  • ▸$480K pre-seed raised from Iterative (YC for SEA) & Accelerating Asia
  • ▸50+ shop locations onboarded in 6 months
  • ▸$1.37M GMV with 200% month-over-month growth
ReactNode.jsPostgreSQLAWS
~/projects/crypto-trade-matching-engine.md
5K+ concurrent orders

Crypto Trade Matching Engine

@ PDAX

Core trade matching engine for a BSP-regulated cryptocurrency exchange, designed for horizontal scaling during market volatility.

// challenge

Building a regulated crypto exchange from scratch in the Philippines with no existing infrastructure.

// impact
  • ▸Sub-100ms matching latency at 5K+ concurrent orders
  • ▸Grew to a top-3 BSP-regulated exchange in the Philippines
  • ▸99.9% platform uptime during major market events
Node.jsRedisPostgreSQLWebSocketSolidity
~/projects/ai-powered-developer-tooling.md
25% faster shipping

AI-Powered Developer Tooling

@ StashAway

MCP-based automated code review and test generation pipeline to accelerate engineering output.

// challenge

Senior engineers spent 30% of their time on routine PR reviews, creating a bottleneck for the entire team.

// impact
  • ▸Review turnaround cut by 50%
  • ▸Team shipping speed increased by 25%
  • ▸Freed senior engineers for architecture work
MCPRAGVector DBsn8nNestJS
04. tech_stack.tsx

//Tech Stack

/* Tools and technologies I work with daily */

import * as Languages
from '@/languages';
JavaScriptTypeScriptPythonGoSolidity
import * as BackendFrontend
from '@/backend-and-frontend';
Node.jsNestJSTemporal WorkflowsRESTgRPCn8nReactReact NativeRedux
import * as AILLM
from '@/ai-and-llm';
MCPRAG PipelinesVector DBsPineconepgvectorLLM Context ManagementAgentic Workflows
import * as DataStorage
from '@/data-and-storage';
PostgreSQLMongoDBDynamoDBRedisPineconeTimescaleDB
import * as CloudInfrastructure
from '@/cloud-and-infrastructure';
AWSKubernetesTerraformHelmDockerCI/CD
import * as MessagingStreaming
from '@/messaging-and-streaming';
Apache KafkaRabbitMQAWS SQSFlink
import * as Observability
from '@/observability';
DatadogGrafanaPagerDutyOpsGenieSentrySplunk
import * as DataAnalytics
from '@/data-and-analytics';
DatabricksRedashLookerMetabase
05. get_in_touch.tsx

//Get in Touch

/* Have a project in mind or want to connect? I'd love to hear from you. */

// contact_details

Email

adarshkumar2k@gmail.com

Phone

+91 9599401658

+60 135308971

Location

Kuala Lumpur, Malaysia

LinkedIn

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