# Lookup Published articles for Lookup. This is one page of public article previews, not the complete archive. Follow Next page to continue. Summaries are not the original full articles. ## How to Approve Real Users and Block Fake Accounts at Sign Up with Lookup and Verify in PHP DevFeed: [How to Approve Real Users and Block Fake Accounts at Sign Up with Lookup and Verify in PHP]() Original publisher: [Read original article]() Author: Kelley Robinson, Matthew Setter Published: 2026-08-31T00:00:00Z Content type: tutorial Language: en Sources: [Twilio Blog]() Topics: [PHP](), [API](), [Tutorial](), [data](), [Code]() Tags: [api](), [code](), [developer-insights](), [fake-accounts](), [fraud](), [github](), [how-to](), [lookup](), [onboarding](), [php](), [sign-up](), [verifications-and-identity](), [verify]() ### AI overview This tutorial shows how to use Twilio Lookup and Verify with PHP to collect a user's name and phone number, apply layered phone and identity checks, and block likely fake accounts during sign-up. ### Source excerpt Learn how to collect a user's name and phone number and conduct a multi-step orchestrated identity verification flow with Twilio's Lookup API. ## How to Confirm Phone Number Ownership with Lookup Identity Match in PHP DevFeed: [How to Confirm Phone Number Ownership with Lookup Identity Match in PHP]() Original publisher: [Read original article]() Author: Kelley Robinson, Matthew Setter Published: 2026-08-31T00:00:00Z Content type: tutorial Language: en Sources: [Twilio Blog]() Topics: [PHP](), [API](), [.env]() Tags: [account](), [and-best-practices](), [api](), [code](), [developer-insights](), [fraud](), [how-to](), [lookup](), [php](), [tutorials](), [verification](), [verify](), [zero-knowledge]() ### AI overview This tutorial explains how to use Twilio Lookup Identity Match with PHP to confirm whether details such as a name, address, national ID, or date of birth match a phone number. It covers setup requirements, project configuration, and collecting the information needed for the match. ### Source excerpt Send details like name, address, or date of birth and the Identity Match API will tell you if they match a provided phone number. Reduce fraud and verify identities quickly in PHP. ## How to Approve Real Users and Block Fake Accounts at Sign Up with Lookup and Verify in C# DevFeed: [How to Approve Real Users and Block Fake Accounts at Sign Up with Lookup and Verify in C#]() Original publisher: [Read original article]() Author: Amanda Lange, Dhruv Patel, Kelley Robinson Published: 2026-08-28T00:00:00Z Content type: tutorial Language: en Sources: [Twilio Blog]() Topics: [C#](), [API](), [.NET 9]() Tags: [auth](), [c-sharp](), [developer-insights](), [fake-accounts](), [fraud](), [how-to](), [lookup](), [onboarding](), [sign-up](), [verification](), [verify]() ### AI overview This tutorial shows C# developers how to combine Twilio Lookup and Twilio Verify to screen phone numbers during sign-up, verify identity, and block fake accounts. It covers line-type, reachability, identity-match, and phone-possession checks. ### Source excerpt How to Approve Real Users and Block Fake Accounts at Sign Up with Lookup and Verify in C Sharp ## How DNS Works for DevOps Engineers DevFeed: [How DNS Works for DevOps Engineers]() Original publisher: [Read original article]() Author: Pramodh Kumar M Published: 2026-07-31T17:00:06Z Content type: tutorial Language: en Sources: [Kubernetes - KodeKloud Blog | DevOps, Cloud, Kubernetes, AI Tutorials & More]() Topics: [DevOps](), [Internet](), [Kubernetes](), [Security]() Tags: [1-1-1-1](), [authoritative-name-server](), [cloudflare](), [cname-vs-a-record](), [coredns-kubernetes](), [devops](), [dig-command-examples](), [dns](), [dns-for-devops-engineers](), [dns-record-types](), [dns-resolution-process](), [dns-troubleshooting](), [guide](), [health-checks](), [how-dns-works](), [infrastructure](), [kubernetes](), [linux](), [lookup](), [networking](), [outage](), [production](), [recursive-resolver](), [security](), [troubleshooting](), [ttl-in-dns](), [web]() ### AI overview A practical guide to DNS for DevOps engineers, tracing a lookup from a laptop through recursive, root, TLD, and authoritative servers. It explains TTL, caching, Kubernetes DNS and ndots, troubleshooting with command-line tools, and the security risk of dangling records. ### Source excerpt Almost every engineer uses DNS a hundred times a day and has never been taught how it works. This guide follows a single lookup from your laptop to the answer, then shows you exactly where it breaks in production. ## Shazam finds songs by voting on time offsets, not by comparing audio DevFeed: [Shazam finds songs by voting on time offsets, not by comparing audio]() Original publisher: [Read original article]() Author: hello@ankit-rana.com Published: 2026-03-16T00:00:00Z Content type: tutorial Language: en Sources: [Ankit Rana | Mechanical Sympathy]() Topics: [Algorithm](), [hash](), [Databases]() Tags: [algorithm](), [algorithms](), [audio-fingerprinting](), [databases](), [hash](), [indexing](), [lookup](), [music-recognition](), [query](), [system-design]() ### AI overview The article explains how Shazam recognizes songs from short, noisy recordings. Instead of comparing audio similarity, it extracts spectrogram peaks, combines nearby peaks into hashes, and uses an inverted index to find tracks whose hash matches share a common time offset. The production system beyond the public 2003 paper is noted as unavailable. ### Source excerpt Shazam does not compare audio. It reduces each track to spectrogram peaks, pairs nearby peaks into ~32-bit hashes, and looks those up in an inverted index. A match is declared when many hashes from the sample agree on a single time offset into one track. The offset histogram is the whole trick: noise scatters offsets randomly, a real match stacks them into a spike. ## Keycloak Federated Client Authentication with External Identity Providers DevFeed: [Keycloak Federated Client Authentication with External Identity Providers]() Original publisher: [Read original article]() Author: Stian Thorgersen Published: 2026-01-26T00:00:00Z Content type: tutorial Language: en Sources: [Keycloak Blog]() Topics: [Keycloak](), [Authentication](), [JSON Web Tokens](), [openid](), [SPIFFE](), [Kubernetes](), [trust]() Tags: [authentication](), [idm](), [jwt](), [kerberos](), [keycloak](), [kubernetes](), [ldap](), [lookup](), [openid](), [openid-connect](), [saml](), [signing](), [spiffe](), [sso](), [token](), [verify]() ### AI overview Keycloak's federated client authentication lets OpenID Connect clients authenticate through external identity providers such as OpenID Connect, SPIFFE, and Kubernetes. The article explains trust relationships, JWT claims, token verification, and how this can reduce the need for client-managed secrets in some environments. ### Source excerpt Keycloak has from day one supported identity brokering, allowing users to authenticate via an external OpenID Connect or SAML 2.0 identity provider. With federated client authentication it is now possible to authenticate OpenID Connect clients through external identity providers as well. Depending on the environment the clients is running in this can eliminate the need for managing secrets for clients altogether. A number of cloud vendors for example support injecting tokens automatically for workloads, Kubernetes have support for service accounts, and last but not least there is SPIFFE that can be leveraged in most environments. How does federated client authentication work? The first step to setting up federated client authentication is to define a trust relationship between Keycloak and the external identity providers. This is done by creating a new identity provider in the realm. Keycloak currently has three types of identity providers that support federated client authentication: OpenID Connect SPIFFE Kubernetes Clients can retrieve a token from the external identity providers that the client can then use to authenticate with Keycloak. In many cases clients can retrieve these tokens automatically through workload identity capabilities enabled for particular environments. Let's look at an example decoded JWT that can be used to authenticate a client: { "iss" : "https://my-external-idp" "aud" : [ "http://my-keycloak/realms/myrealm" ], "exp" : 1769149961, "iat" : 1769149661, "sub" : "client-id-in-my-external-idp" } The most relevant claims are iss, aud and sub. Keycloak uses the iss claim to identity the external party that issued the token as well as retrieving the external parties signing keys to verify the token. The aud claim is to make sure the token was issued to be used by Keycloak and not other applications. It is important that this contains a single audience that uniquely identifies Keycloak as the target audience, as leaking this token to other parties ## New Concurrent Hash Maps for C++ DevFeed: [New Concurrent Hash Maps for C++]() Original publisher: [Read original article]() Author: Jeff Preshing Published: 2016-02-01T13:30:00Z Content type: article Language: en Sources: [Jeff Preshing]() Topics: [C++](), [Concurrency](), [Data structures](), [Library](), [Programming](), [CMake](), [Ubuntu](), [Windows](), [iOS](), [Java]() Tags: [c-plus-plus](), [cmake](), [code](), [concurrent](), [data](), [dependencies](), [efficiency](), [ios](), [java](), [lock-free](), [lookup](), [map](), [os](), [platforms](), [programming](), [structure](), [thread](), [ubuntu](), [windows]() ### AI overview The article introduces Junction, a BSD-licensed C++ library containing concurrent hash maps designed for lock-free, multi-threaded operations. It describes the Linear, Leapfrog, and Grampa map variants, their resizing and lookup strategies, platform support, and atomic operations. ### Source excerpt A map is a data structure that maps a collection of keys to a collection of values. It's a common concept in computer programming. You typically manipulate maps using functions such as find, insert and erase. A concurrent map is one that lets you call some of those functions concurrently - even in combinations where the map is modified. If it lets you call insert from multiple threads, with no mutual exclusion, it's a concurrent map. If it lets you call insert while another thread is calling find, with no mutual exclusion, it's a concurrent map. Other combinations might be allowed, too. Traditional maps, such as std::map and std::unordered_map, don't allow that. Today I'm releasing Junction, a C++ library that contains several new concurrent maps. It's BSD-licensed, so you can use the source code freely in any project, for any purpose. On my Core i7-5930K, Junction's two fastest maps outperform all other concurrent maps. They come in three flavors: Junction's Linear map is similar to the simple lock-free hash table I published a while ago, except that it also supports resizing, deleting entries, and templated key/value types. It was inspired by Cliff Click's non-blocking hash map in Java, but has a few differences. Junction's Leapfrog map is similar to Linear, except that it uses a probing strategy loosely based on hopscotch hashing. This strategy improves lookup efficiency when the table is densely populated. Leapfrog scales better than Linear because it modifies shared state far less frequently. Junction's Grampa map is similar to Leapfrog, except that at high populations, the map gets split into a set of smaller, fixed-size Leapfrog tables. Whenever one of those tables overflows, it gets split into two new tables instead of resizing the entire map. Junction aims to support as many platforms as possible. So far, it's been tested on Windows, Ubuntu, OS X and iOS. Its main dependencies are CMake and a companion library called Turf. Turf is an abstraction layer over