Dhali Abir — Senior Software & Security Engineer | Backend, System Design, Oracle DB

About

The engineer behind the uptime.

experience8+ years

focusbackend · security

based_inremote / hybrid

status● available

I'm Dhali Abir — a senior engineer who spends most days moving between two roles: building the backend systems a product runs on, and making sure they hold up under real-world pressure. Over 8+ years I've shipped REST APIs and service architectures for fintech and healthcare platforms, led Oracle database migrations with zero downtime, and run security reviews that caught what automated scanners missed.

I care about systems that are boring in the best way: predictable under load, clear to reason about, and hard to compromise. That means writing SQL that scales past the demo, designing APIs other teams actually enjoy integrating with, and treating security as a design constraint from day one — not a checklist bolted on before launch.

Backend Development96%

System Design93%

Oracle Database / SQL90%

Security Engineering91%

Node.js / REST APIs95%

Cloud & Infrastructure85%

Services

Modules I run in production.

active

Backend Development

Robust, well-tested services built on Node.js — from clean domain models to background jobs that don't quietly fail.

:3000

active

Security Engineering

Threat modeling, secure code review, and remediation — reducing real attack surface, not just findings on a report.

:443

active

System Design

Architecture that scales on paper and in production — capacity planning, failure modes, and clear trade-off documentation.

:8080

active

Oracle Database Architecture

Schema design, query tuning, and zero-downtime migrations for systems where the database is the bottleneck no one sees coming.

:1521

active

REST API Development

Predictable, versioned, well-documented APIs — designed for the teams that have to integrate with them six months from now.

:4000

active

Technical Consulting & Code Review

An outside senior eye on your architecture, your data layer, or your incident post-mortems — before small issues compound.

:9000

Portfolio

Selected projects & case studies.

Zero-Trust Payments Gateway

Rebuilt a legacy payments API with a zero-trust security model and full audit trail.

Node.jsOracleOAuth2

FINTECH2024

Multi-Region Order Platform

Designed an event-driven order system handling regional failover with sub-second recovery.

System DesignRESTKafka

E-COMMERCE2023

Oracle-to-Cloud Migration

Led a zero-downtime migration of a 40TB Oracle estate for a healthcare records provider.

Oracle DBSQLHIPAA

HEALTHCARE2023

Internal AppSec Program

Built a company-wide secure-SDLC program: threat modeling, SAST/DAST pipelines, and training.

AppSecCI/CDSAST

SECURITY2022

Public REST API Platform

Designed and shipped a versioned partner API now used by 60+ integrators, with rate-limiting and keys.

REST APIsNode.jsRedis

PLATFORM2022

High-Volume Query Optimization

Rewrote core reporting queries and indexing strategy, cutting P95 latency on a 2B-row Oracle table.

Oracle DBSQL TuningSystem Design

DATA2021

Blog

Notes from production.

2026-06-14

Why "it passed the pen test" isn't a security strategy

A look at how point-in-time testing misses the security issues that actually get exploited.

2026-04-02

Indexing strategy for tables that never stop growing

Practical lessons from tuning Oracle tables well past the point where "just add an index" stops working.

2026-01-19

Designing REST APIs for the team that inherits them

Versioning, error shapes, and documentation habits that save the next engineer a bad afternoon.

2025-11-08

System design interviews, from the interviewer's side

What actually separates a strong answer from a memorized framework, after running 100+ interviews.

menu.json

Building backend systems that don't fall over — or get broken into.

The engineer behind the uptime.

Modules I run in production.

Backend Development

Security Engineering

System Design

Oracle Database Architecture

REST API Development

Technical Consulting & Code Review

Selected projects & case studies.

Zero-Trust Payments Gateway

Multi-Region Order Platform

Oracle-to-Cloud Migration

Internal AppSec Program

Public REST API Platform

High-Volume Query Optimization

Notes from production.

Why "it passed the pen test" isn't a security strategy

Indexing strategy for tables that never stop growing

Designing REST APIs for the team that inherits them

System design interviews, from the interviewer's side

Let's build something reliable.