Salayhin Md Sirajus | Staff Data Platform Engineer

Experience

Staff Data Platform Engineer

Zeals Co., Ltd · Senior Data & Infrastructure Engineer → Senior Data Platform Engineer → Staff Data Platform Engineer (promoted Nov 2023)

Tokyo, Japan (joined remotely, relocated 2022) Apr 2021 - Present

Current

Sole architect and primary technical decision-maker for the company-wide data platform that analytics, ML, and BI teams self-serve on — owning architecture reviews, tooling decisions, and platform standards across the data organization, and operating the BI layer (Tableau, Redash) as platform-managed services.

Architected and operate a production Apache Iceberg lakehouse on GCS (BigLake Metastore) with dual-engine access via BigQuery and Spark on Dataproc — chosen for cost, multi-engine reads without duplication, and protobuf schema evolution.

Built the team's core pipeline framework — a Docker- and script-driven system that provisions and manages ephemeral Dataproc clusters — running Scala/Spark ingestion of ~100 GB/day (peaks ~1 TB) of protobuf event streams from Pub/Sub through landing → bronze → gold medallion layers, with automated Iceberg table maintenance (compaction, snapshot expiry) — orchestrated end-to-end on Cloud Composer (Airflow), the platform's primary orchestrator.

Drove a platform-wide cost program spanning BigQuery optimization and the Iceberg migration, lowering monthly spend ~60% (¥1.2M → under ¥500K).

Optimized BigQuery workloads using system tables and billing exports — partitioning, clustering, and gold-layer star-schema modeling (dim_/fact_ tables) — reducing query runtime by up to 90% and scan volume by 80%.

Led adoption of dbt Cloud with CI/CD, testing, and documentation standards — now the platform's modeling layer, where analytics engineers build and own models — cutting data incidents reaching stakeholders from 2–3/month to under one every two months, and pipeline maintenance from 1–2 days/week to a few hours.

Own platform governance and security: column-level PII masking at ingest backed by BigQuery policies, GDPR right-to-erasure across Iceberg tables and snapshots, cloud resources and IAM managed as Infrastructure-as-Code via Terraform with PR review, end-to-end data lineage and metadata via dbt and GCP-native lineage tracking, and partnered with security engineers on SOC 2 compliance for the analytics layer.

Shipped a FinOps & observability suite running on GKE (Kubernetes): daily cost collection across all GCP projects with billing-based actuals, expensive-query and cache-miss alerts, BigQuery freshness and quota alerts, and a central observability dashboard.

Designed a custom MCP server for governed, AI-assisted analytics on BigQuery — schema discovery and self-service, plain-language querying of business metrics, restricted to gold tables via a security layer; championed team AI adoption (Claude Code enablement, best practices, custom skills, AI-assisted code review).

Standardized CI/CD deployment via GitHub Actions across all platform workloads — Spark pipelines and dbt models alike ship through automated pipelines; defined data contracts, quality standards, and SLAs across teams; mentored junior engineers.

Apache Iceberg BigQuery Scala / Spark dbt Terraform Pub/Sub MCP

Senior Data Engineer Level 2

Pathao Ltd

Dhaka, Bangladesh Jun 2018 - May 2021

Designed and operated batch and near-real-time telemetry pipelines (trip lifecycle, GPS location streams, driver/rider actions) for 100K+ daily trips across ride-sharing, courier, and food delivery — spanning multiple cities across Bangladesh and Nepal

Implemented data pipelines integrating transaction data from 20+ sources plus streaming data at high volume (~50 GB/day) and velocity (peaks of 10K events/sec) on Spark, Dataflow, GCS, and Airflow

Created the metrics framework computing 100+ business KPIs (driver earnings, leaderboards, operational metrics) with under-5-minute end-to-end latency

Spearheaded the company's data lake and 10 TB BigQuery data warehouse on Google Cloud Storage, halving data retrieval times

Established the analytics ecosystem on Dataproc, Dataflow, BigQuery, and Data Studio, and delivered a scheduled reporting framework generating 10+ financial and operational reports

Dataproc BigQuery Dataflow Python

Senior Data Engineer

Augmedix Bangladesh Ltd.

Dhaka, Bangladesh Jun 2015 - Mar 2018

Core contributor to the design and build of a SQL Server 2016 data warehouse on AWS (S3-backed storage) supporting company-wide business reporting

Developed AWS data pipelines (S3, Lambda) consolidating data from third-party APIs, Google Sheets, and MySQL (100+ attributes), and a reporting suite producing 20+ operational reports

Delivered backend services serving millions of warehouse records to internal applications

SQL Server MySQL Data Pipeline APIs

Software Engineer

Nascenia Ltd

Dhaka, Bangladesh Jun 2013 - May 2015

Launched a B2B agricultural marketplace platform with Ruby on Rails and MySQL

Developed a social media analytics and post-scheduling tool with Rails and PostgreSQL

Ruby on Rails MySQL PostgreSQL Web Development

Software Engineer

Right Brain Solution Ltd

Dhaka, Bangladesh Nov 2011 - May 2013

Co-authored a high-traffic automotive portal for the Toronto Star

Created APIs for social media mobile apps and a multilingual B2C ski-rental e-commerce platform

API Development Web Applications Mobile Apps OMR Systems