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A modern, spreadsheet UI for Enriching CRM data

ApolloHacks 2025 sparked one of Apollo’s an exciting design innovation: the Spreadsheet UI to enrich CRM data. Designed for speed, simplicity, and scale, it transforms complex enrichment workflows into an intuitive, spreadsheet-like experience. Users can view, update, and enrich thousands of records with minimal clicks and real-time feedback, all within a single, unified grid. Backed by powerful virtualization and smart interaction design, this modern UI delivers high performance and clarity for data-driven teams.

October 27, 2025

Design

Engineering

Software

October 27, 2025

Design

Engineering

Software

Intelligent Email Deliverability Debugging

Apollo transformed email deliverability with an AI-powered agent that cuts debugging time from weeks to minutes. Built with the ReACT framework, it systematically analyzes metrics, authentication, bounce logs, and domain setup to pinpoint issues and offer real-time solutions. Continuous evals ensure reliability, while an updated knowledge base keeps the agent current with Apollo’s evolving features. By combining systematic analysis with domain expertise, Apollo turned a complex, frustrating process into a streamlined, AI-assisted experience, helping users maximize inbox reach and ROI faster than ever before.

September 17, 2025

Engineering

Software

September 17, 2025

Engineering

Software

AI Tagging : From Feedback To Actions

Apollo automated customer feedback tagging with AI + LLMs, scaling VOC insights, boosting CIR accuracy, and reducing manual effort—transforming customer complaints into product action.

August 26, 2025

Engineering

Software

August 26, 2025

Engineering

Software

Pierogis & Pull Requests: Apollo’s Poland Offsite

There’s something magical about seeing your remote teammates materialize in real life. You know these people through GitHub comments, Zoom calls, and Slack messages. But suddenly, they’re there in a Kraków 🇵🇱 hotel lobby, holding a coffee, making actual eye contact. And for a moment, your brain short-circuits. From July ...

August 19, 2025

Culture

Engineering

August 19, 2025

Culture

Engineering

Friction to Fortress: How Turnstile Shields Apollo

Apollo engineered a modern, privacy‑first security system using Cloudflare® Turnstile to block millions of malicious login and API attacks without disrupting legitimate users. By combining adaptive challenges, edge enforcement, and data‑driven signals, we reduced operational overhead, improved login success rates, and protected user trust at scale — all while preparing for future growth.

July 29, 2025

Engineering

Software

July 29, 2025

Engineering

Software

Waterfall: A Modular, Rate-Aware Data Engine

"Discover how Apollo’s Data Waterfall engine transformed multi-vendor data enrichment—delivering higher fill rates for emails and phone numbers, faster scaling, and lower costs for millions of enriched contacts daily.

July 25, 2025

Engineering

July 25, 2025

Engineering

ApolloHacks '25 : Part I

Unlocking new growth, Apollo’s latest edition of their annual hackathon ApolloHacks 2025 delivered two game-changing projects: a multi-lingual website to reach non-English speaking markets, and a mobile-first experience that empowers sales teams to access data and update leads from anywhere. With these innovations, Apollo IO is now more global and truly on the go.

June 4, 2025

Culture

Engineering

June 4, 2025

Culture

Engineering

Speedy Search Via 2-Phase Scoring

How We Tamed Complex Queries Without Slowing Down the Universe If you’ve ever built a search engine that supports custom scoring , you’re probably familiar with the “Latency Monster” that shows up as your scoring logic grows more complex. At Apollo, our users define intricate scoring criteria—“Give me +30 points ...

May 27, 2025

Engineering

Software

May 27, 2025

Engineering

Software

Fighting Noise In Email Tracking

Email engagement signals like opens and clicks help sales teams trigger workflows and prioritise leads. But providers like Google and Apple now use bots to scan emails, inflating open rates and distorting real engagement. Apollo solves this by filtering out bot activity, helping teams focus only on genuine human interactions and drive better conversions.

April 24, 2025

Engineering

Software

April 24, 2025

Engineering

Software

Prospect Recommendation 2.0

Discover how Apollo enhances prospect recommendations with team collaboration and index optimization, boosting coverage, reducing costs, and maintaining accuracy. Join us in our AI-driven journey!

April 14, 2025

Engineering

Software

April 14, 2025

Engineering

Software

Few people sitting on a rock near a beach. Few boats are visible in the sea and an old man is doing something in the background,

Engineering Offsite: Sun, Code & Celebrations

Apollo’s global remote-first team gathered in Goa for our biggest offsite yet. Over 150 teammates from Engineering, Product, and People came together to learn, connect, and celebrate in person—stepping away from Zoom and Slack for real conversations, collaboration, and community.

April 13, 2025

Culture

April 13, 2025

Culture

Cross-Entity Searching - Part 1

At Apollo, our mission to build a leading Sales Platform brings with it a variety of complex customer use cases. Our goal is to support these use cases in the most intuitive and user-friendly manner possible. One such intricate challenge is enabling searches across multiple Apollo entities ...

April 2, 2025

Engineering

Product

April 2, 2025

Engineering

Product

A fresh look at Apollo: elevating our visual identity

Apollo’s design refresh unifies brand and product, enhancing clarity, usability, and aesthetics with a new identity, dark mode, and a scalable design system. Learn how Apollo’s design and engineering team pulled it off!

February 21, 2025

Design

Engineering

Product

Visuals

February 21, 2025

Design

Engineering

Product

Visuals

Detecting Data Duplication at Scale

Discover how Apollo.io tackled duplicate accounts with a scalable deduplication tool. Learn about root cause analysis, data pipelines, and automation that improved data quality, reduced customer escalations, and enhanced operational efficiency.

January 29, 2025

Engineering

January 29, 2025

Engineering

Ingesting 100TB from MongoDB Weekly

In this blog, we’re diving into how Apollo’s Data Platform team ingests 100TB of MongoDB data weekly—from 270TB of disks across 6 clusters and 120 shards—without impacting production. The challenge? Ingesting massive datasets within a 6-hour window for BI reporting. After testing Fivetran and open-source tools like Spark, the team found them too slow. Instead, they spun up dedicated ingestion clusters from snapshots and optimized mongoexport by querying shards directly. This scaled the process to 20TB collections in just 30 minutes. By bypassing routers and using efficient parallelization, the team built a cost-effective, high-performance pipeline, providing data for BI, ML/AI, and Security at just $2,000/week. Their story exemplifies Apollo’s commitment to innovation and resourcefulness.

January 10, 2025

Big Data

Data Ingestion

Data Pipeline

Mongo

January 10, 2025

Big Data

Data Ingestion

Data Pipeline

Mongo

Distinguished Engineer Series: Aidan Li, Sr Director - Product, Platform & Growth

Today, we talk about Aidan Li, Apollo’s Director of Engineering for Core Product, Platform, and Growth, who embodies technical excellence and leadership. Starting as a Software Engineer in 2019, Aidan has been a driving force behind Apollo’s growth—building company-wide frameworks, improving incident management, and leading key product initiatives. His people-first approach, mentorship, and problem-solving make Apollo a place where engineers thrive and innovate. If you’re looking for a place to grow with exceptional leaders, Apollo is the perfect fit.

January 10, 2025

Culture

Engineering

Leadership

Software

January 10, 2025

Culture

Engineering

Leadership

Software

Building Apollo's New Home

Discover how Apollo's new personalized homepage, powered by a Dynamic Page Framework and modular Widgets Library, enhances feature discovery, user productivity, and ROI through customization at scale.

December 17, 2024

Engineering

Product

Software

December 17, 2024

Engineering

Product

Software

Getting Launch Ready : Quality & Resilience On Production

Writing production-ready code is crucial for building robust, fault-tolerant systems. This guide highlights common pitfalls and provides actionable steps to improve code quality, ensuring reliability and minimizing failures. Let’s dive in⚡️.

November 8, 2024

Engineering

Software

November 8, 2024

Engineering

Software

Email Reply Classification Done Right

At Apollo.io , we're constantly working to improve our platform for Sales Development Representatives (SDRs) across various organizations. One common challenge our users face is managing the overwhelming volume of email responses they receive daily. SDRs often struggle to quickly identify and prioritize important replies amidst a sea of out-of-office ...

August 23, 2024

Engineering

Software

August 23, 2024

Engineering

Software

Solving ID type confusion in Mongoid

Apollo’s Context Apollo.io backend codebase is fully based on Ruby on Rails and contained within a single GitHub Monorepo. This allows us to centralize quality control, and database communication. We also use multiple MongoDB clusters with collections containing billions of documents. It’s crucial for developer productivity to have a common ...

August 9, 2024

Engineering

Mongo

Software

August 9, 2024

Engineering

Mongo

Software

The mentor I never knew I needed 🪄

🌴 Branching my way out of the deep end There was a project which was essentially a “relay race” of engineers working in sequence. Before we started, I had a chat with Umang, my mentor and Staff Frontend Engineer for the Growth team, about how to handle merging my changes ...

August 9, 2024

Culture

Engineering

Software

August 9, 2024

Culture

Engineering

Software

Detecting Dangerous MongoDB Queries

📈 Querying MongoDB at scale Here at Apollo, we use MongoDB as our main database store and Mongoid on Ruby as our interface to the DB. The larger collections that are routinely used by our user-facing features can range from tens of millions to tens of billions of documents, so ...

July 10, 2024

Database

Engineering

Software

July 10, 2024

Database

Engineering

Software

Building the Orum Integration with Apollo

I’m Melissa Reffsin, Product Manager at Orum. You might be wondering who I am, what Orum is, and what I’m doing writing an article for Apollo’s new tech blog! What Is Orum ? Orum is an AI-powered live conversation platform driving more pipelines for sales organizations. With Orum, users automate ...

April 10, 2024

Engineering

April 10, 2024

Engineering

Analytics at Scale @ Apollo.io

Apollo seeks to empower GTM teams with an end-to-end platform for all their sales needs, from finding the right customers to winning deals. Within every step in their journey at Apollo, analytics enables customers to deep dive into their metrics and performance. Like a trusted “sherpa”, ...

April 10, 2024

Engineering

Product

Software

April 10, 2024

Engineering

Product

Software

A before and after of a person at a laptop, first frustrated but then happy.

Overcoming Boreout In Remote Teams

Apollo is an all-remote company, and we have team members working in 30+ countries. We are constantly building on our offerings and readjusting or reevaluating processes to support all team members the best way we can, but remote collaboration can sometimes be challenging. So, how can we best collaborate and continue to move fast while working across different time zones? Or, more importantly, how can we avoid reaching Zoom fatigue and the seemingly inevitable state of understimulated ‘boreout’?...

February 5, 2024

Culture

Design

February 5, 2024

Culture

Design

How Apollo Builds Product

It’s no secret that “product” can mean a lot of different things at different companies. Today I'm thrilled to peel back the curtain and share insights into our unique approach to product development. The Power of Impact and Agency As an Apollo PM Embarking ...

February 5, 2024

Product

February 5, 2024

Product

Distinguished Engineer Series: Himanshu Gahlot, VP Engineering, Data and Intelligence

Himanshu Gahlot, a Senior Director of Engineering at Apollo.io, brings a wealth of experience and expertise to the tech domain. Currently overseeing data and machine learning initiatives, he leads a globally distributed team of 100+ individuals across various verticals. Most importantly, he’s also my boss, so I wanted to highlight ...

January 31, 2024

Culture

Engineering

January 31, 2024

Culture

Engineering

Building Apollo’s Data & Machine Learning Platform

Data is at the core of Apollo’s business. The company started as a sales prospecting data vendor before becoming the all-in-one sales platform. Sales prospecting continues to be the one of the most fundamental and important parts of our business portfolio. Building and maintaining such a big data business comes ...

January 24, 2024

Engineering

January 24, 2024

Engineering

Engineering Focus and Rest Days

In the fast-paced world of technology, fostering an environment that nurtures innovation and productivity is paramount. At Apollo, we understand the importance of providing our engineering teams with the ideal conditions to excel in their work. I wanted to throw together a blog post to talk about a few angles ...

January 24, 2024

Culture

Engineering

January 24, 2024

Culture

Engineering

The Beginnings of Apollo

I'm Tim Zheng, co-founder and CEO of Apollo.io, and I'm thrilled to share the journey behind the inception of Apollo and the culture we are building. Over the last few years at Apollo, I've found that our Product and our Culture have both changed significantly and have been major drivers ...

January 23, 2024

Culture

January 23, 2024

Culture